## File: README.md # Universal Ctags [](https://scan.coverity.com/projects/4355) [](https://coveralls.io/github/universal-ctags/ctags?branch=master) [](https://ci.appveyor.com/project/universalctags/ctags/branch/master) [](https://docs.ctags.io) [](https://dl.circleci.com/status-badge/redirect/gh/universal-ctags/ctags/tree/master) [](https://gurubase.io/g/universal-ctags) [Universal Ctags](https://ctags.io/) (abbreviated as u-ctags) is a *maintained* implementation of `ctags`. `ctags` generates an index (or tag) file of language objects found in source files for programming languages. This index makes it easy for text editors and other tools to locate the indexed items. [Exuberant Ctags](http://ctags.sourceforge.net/) (e-ctags) maintained by Darren Hiebert, the ancestor of Universal Ctags, improved traditional `ctags` with multi-language support, the ability for the user to define new languages searched by regular expressions (called optlib in Universal Ctags), and the ability to generate emacs-style TAGS files. But the activity of the project unfortunately stalled. Universal Ctags has the objective of continuing the development of Exuberant Ctags. Reza Jelveh initially created a personal fork of Exuberant Ctags on GitHub. As interest and participation grew, it was decided to move development to a dedicated project as Universal Ctags. The goal of this project is to maintain a common/unified working space where people interested in making ctags better can work together. Some of the major features of Universal Ctags are: * more numbers of improved language support * new extended C/C++ language parser, etc. * fully extended optlib (a feature to define a new language parser from a command line) * interactive mode (experimental) ## The latest build and package ## If you want to try the latest Universal Ctags without building it yourself... ### Windows Daily builds are available at the [ctags-win32](https://github.com/universal-ctags/ctags-win32) project. Go to the [releases](https://github.com/universal-ctags/ctags-win32/releases) page to download zip packages. ### Unix-like Nightly builds are available at the [ctags-nightly-build](https://github.com/universal-ctags/ctags-nightly-build) project. Go to the [releases](https://github.com/universal-ctags/ctags-nightly-build/releases) page to download tarball archives. ### Mac Recent builds are available via the [`universal-ctags` Homebrew formula](https://formulae.brew.sh/formula/universal-ctags). ### Snap Go to [ctags-snap](https://github.com/universal-ctags/ctags-snap) and clone the `ctags-snap` repo. Then, follow instructions to build the snap package of Universal Ctags. Snapcraft will automatically fetch the source code from GitHub. ## How to build and install ## To build with Autotools (Autoconf and Automake) on GNU/Linux, OSX, or Windows 10 WSL, ``` $ git clone https://github.com/universal-ctags/ctags.git $ cd ctags $ ./autogen.sh $ ./configure # use --prefix=/where/you/want to override installation directory, defaults to /usr/local $ make $ make install # may require extra privileges depending on where to install ``` GNU make is assumed as the `make` command. See [`docs/autotools.rst`](https://github.com/universal-ctags/ctags/blob/master/docs/autotools.rst) for more information. To build on Windows, see [`docs/windows.rst`](https://github.com/universal-ctags/ctags/blob/master/docs/windows.rst) for more information. To build on OSX, see [`docs/osx.rst`](https://github.com/universal-ctags/ctags/blob/master/docs/osx.rst) for more information. ## Manual ## The primary documents of Universal Ctags are man pages. Users should first consult the [ctags(1)](https://docs.ctags.io/en/latest/man/ctags.1.html), and [other man pages](https://docs.ctags.io/en/latest/man-pages.html) if necessary. [Universal Ctags Hacking Guide](https://docs.ctags.io), which also includes the man pages, is primarily for developers and provides additional information to the man pages, including experimental features. See also `*/README.md` on this repository. ## Differences from exuberant-ctags ## You may be interested in how Universal Ctags is different from Exuberant Ctags. See [ctags-incompatibilities(7)](https://docs.ctags.io/en/latest/man/ctags-incompatibilities.7.html) and [Introduced changes](https://docs.ctags.io/en/latest/news.html) for details. The most significant incompatible changes: * Universal Ctags doesn't load `~/.ctags` and `./.ctags` at starting up time. Instead, it loads `~/.ctags.d/*.ctags` and `./.ctags.d/*.ctags`. * Universal Ctags is more strict about characters that can be used in kind letters and kind names than Exuberant-ctags. - The letter must be an alphabetical character (`[a-zA-EG-Z]`). `F` is reserved for `file` kind. - The first character of the name must be alphabetic, and the rest characters must be alphanumeric (`[a-zA-Z][a-zA-Z0-9]*`). The detailed background is explained in [#1737](https://github.com/universal-ctags/ctags/pull/1737). If you want to reuse your `.ctags` written for Exuberant-ctags, you must review kind letters and names defined with `--regex-=...` options. When updating the definitions, using `--kinddef-=...` option is appreciated. ## [CVE-2022-4515](https://access.redhat.com/security/cve/CVE-2022-4515) ## It is not affected to Universal Ctags. It was fixed in [e00c55d7a0204dc1d0ae316141323959e1e16162](https://github.com/universal-ctags/ctags/commit/e00c55d7a0204dc1d0ae316141323959e1e16162) in 2016. Thanks to the reporter. Pull-requests are welcome! --- ## File: docs/man/ctags.1.rst .. _ctags(1): ============================================================== ctags ============================================================== Generate tag files for source code :Version: 6.2.0 :Manual group: Universal Ctags :Manual section: 1 SYNOPSIS -------- | **ctags** [] [] | **etags** [] [] DESCRIPTION ----------- The *ctags* and *etags* (see ``-e`` option) programs (hereinafter collectively referred to as ctags, except where distinguished) generate an index (or "tag") file for a variety of *language objects* found in *source file(s)*. This tag file allows these items to be quickly and easily located by a text editor or other utilities (*client tools*). A *tag* signifies a language object for which an index entry is available (or, alternatively, the index entry created for that object). Alternatively, ctags can generate a cross reference file which lists, in human readable form, information about the various language objects found in a set of source files. Tag index files are supported by numerous editors, which allow the user to locate the object associated with a name appearing in a source file and jump to the file and line which defines the name. See the manual of your favorite editor about utilizing ctags command and the tag index files in the editor. ctags is capable of generating different *kinds* of tags for each of many different *languages*. For a complete list of supported languages, the names by which they are recognized, and the kinds of tags which are generated for each, see the ``--list-languages`` and ``--list-kinds-full`` options. This man page describes *Universal Ctags*, an implementation of ctags derived from *Exuberant Ctags*. The major incompatible changes between Universal Ctags and Exuberant Ctags are enumerated in :ref:`ctags-incompatibilities(7) `. One of the advantages of Exuberant Ctags is that it allows a user to define a new parser from the command line. Extending this capability is one of the major features of Universal Ctags. :ref:`ctags-optlib(7) ` describes how the capability is extended. Newly introduced experimental features are not explained here. If you are interested in such features and ctags internals, visit https://docs.ctags.io/. COMMAND LINE INTERFACE ---------------------- Despite the wealth of available options, defaults are set so that ctags is most commonly executed without any options (e.g. "``ctags *``", or "``ctags -R``"), which will create a tag file in the current directory for all recognized source files. The options described below are provided merely to allow custom tailoring to meet special needs. Note that spaces separating the single-letter options from their parameters are optional. Note also that the boolean parameters to the long form options (those beginning with ``--`` and that take a ``[=(yes|no)]`` parameter) may be omitted, in which case ``=yes`` is implied. (e.g. ``--sort`` is equivalent to ``--sort=yes``). Note further that ``=1``, ``=on``, and ``=true`` are considered synonyms for ``=yes``, and that ``=0``, ``=off``, and ``=false`` are considered synonyms for ``=no``. Some options are either ignored or useful only when used while running in etags mode (see ``-e`` option). Such options will be noted. ** must precede the ** following the standard POSIX convention. Options taking language names will accept those names in either upper or lower case. See the ``--list-languages`` option for a complete list of the built-in language names. Letters and names ~~~~~~~~~~~~~~~~~ Some options take one-letter flags as parameters (e.g. ``--kinds-`` option). Specifying just letters help a user create a complicated command line quickly. However, a command line including sequences of one-letter flags becomes difficult to understand. Universal Ctags accepts long-name flags in addition to such one-letter flags. The long-name and one-letter flags can be mixed in an option parameter by surrounding each long-name by braces. Thus, for an example, the following three notations for ``--kinds-C`` option have the same meaning:: --kinds-C=+pLl --kinds-C=+{prototype}{label}{local} --kinds-C=+{prototype}L{local} Note that braces may be meta characters in your shell. Put single quotes in such case. ``--list-...`` options shows one-letter flags and associated long-name flags. List options ~~~~~~~~~~~~ Universal Ctags introduces many ``--list-...`` options that provide the internal data of Universal Ctags (See "`Listing Options`_"). Both users and client tools may use the data. ``--with-list-header`` and ``--machinable`` options adjust the output of the most of ``--list-...`` options. The default setting (``--with-list-header=yes`` and ``--machinable=no``) is for using interactively from a terminal. The header that explains the meaning of columns is simply added to the output, and each column is aligned in all lines. The header line starts with a hash ('``#``') character. For scripting in a client tool, ``--with-list-header=no`` and ``--machinable=yes`` may be useful. The header is not added to the output, and each column is separated by tab characters. Note the order of columns will change in the future release. However, labels in the header will not change. So by scanning the header, a client tool can find the index for the target column. .. options that should be explained and revised here ``--list-features`` (done) ``--machinable`` (done) ``--with-list-header`` (done) OPTIONS ------------ ctags has more options than listed here. Options starting with an underscore character, such as ``--_echo=``, are not listed here. They are experimental or for debugging purpose. Notation: ```` is for a variable string ``foo``, ``[ ... ]`` for optional, ``|`` for selection, and ``( ... )`` for grouping. For example ``--foo[=(yes|no)]`` means ``--foo``, ``--foo=yes``, or ``--foo=no``. .. _option_input_output_file: Input/Output File Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``--exclude=`` Add ** to a list of excluded files and directories. This option may be specified as many times as desired. For each file name considered by ctags, each pattern specified using this option will be compared against both the complete path (e.g. ``some/path/base.ext``) and the base name (e.g. ``base.ext``) of the file, thus allowing patterns which match a given file name irrespective of its path, or match only a specific path. If appropriate support is available from the runtime library of your C compiler, then pattern may contain the usual shell wildcards (not regular expressions) common on Unix (be sure to quote the option parameter to protect the wildcards from being expanded by the shell before being passed to ctags; also be aware that wildcards can match the slash character, '``/``'). You can determine if shell wildcards are available on your platform by examining the output of the ``--list-features`` option, which will include ``wildcards`` in the compiled feature list; otherwise, pattern is matched against file names using a simple textual comparison. If ** begins with the character '``@``', then the rest of the string is interpreted as a file name from which to read exclusion patterns, one per line. If pattern is empty, the list of excluded patterns is cleared. Note that at program startup, the default exclude list contains names of common hidden and system files, patterns for binary files, and directories for which it is generally not desirable to descend while processing the ``--recurse`` option. To see the list of built-in exclude patterns, use ``--list-excludes``. See also the description for ``--exclude-exception=`` option. ``--exclude-exception=`` Add ** to a list of included files and directories. The pattern affects the files and directories that are excluded by the pattern specified with ``--exclude=`` option. For an example, you want ctags to ignore all files under ``foo`` directory except ``foo/main.c``, use the following command line: ``--exclude=foo/* --exclude-exception=foo/main.c``. ``--filter[=(yes|no)]`` Makes ctags behave as a filter, reading source file names from standard input and printing their tags to standard output on a file-by-file basis. If ``--sort`` is enabled, tags are sorted only within the source file in which they are defined. File names are read from standard input in line-oriented input mode (see note for ``-L`` option) and only after file names listed on the command line or from any file supplied using the ``-L`` option. When this option is enabled, the options ``-f``, ``-o``, and ``--totals`` are ignored. This option is quite esoteric and is disabled by default. ``--filter-terminator=`` Specifies a ** to print to standard output following the tags for each file name parsed when the ``--filter`` option is enabled. This may permit an application reading the output of ctags to determine when the output for each file is finished. Note that if the file name read is a directory and ``--recurse`` is enabled, this string will be printed only once at the end of all tags found for by descending the directory. This string will always be separated from the last tag line for the file by its terminating newline. This option is quite esoteric and is empty by default. ``--links[=(yes|no)]`` Indicates whether symbolic links (if supported) should be followed. When disabled, symbolic links are ignored. This option is on by default. ``--maxdepth=`` Limits the depth of directory recursion enabled with the ``--recurse`` (``-R``) option. ``--recurse[=(yes|no)]`` Recurse into directories encountered in the list of supplied files. If the list of supplied files is empty and no file list is specified with the ``-L`` option, then the current directory (i.e. '``.``') is assumed. Symbolic links are followed by default (See ``--links`` option). If you don't like these behaviors, either explicitly specify the files or pipe the output of ``find(1)`` into "``ctags -L -``" instead. See, also, the ``--exclude`` and ``--maxdepth`` to limit recursion. Note: This option is not supported on all platforms at present. It is available if the output of the ``--help`` option includes this option. .. TODO(code): --list-features option should support this. ``-R`` Equivalent to ``--recurse``. ``-L `` Read from ** a list of file names for which tags should be generated. If file is specified as '``-``', then file names are read from standard input. File names read using this option are processed following file names appearing on the command line. Options are also accepted in this input. If this option is specified more than once, only the last will apply. Note: file is read in line-oriented mode, where a new line is the only delimiter and non-trailing white space is considered significant, in order that file names containing spaces may be supplied (however, trailing white space is stripped from lines); this can affect how options are parsed if included in the input. ``--append[=(yes|no)]`` Indicates whether tags generated from the specified files should be appended to those already present in the tag file or should replace them. This option is ``no`` by default. ``-a`` Equivalent to ``--append``. ``-f `` Use the name specified by ** for the tag file (default is "``tags``", or "``TAGS``" when running in etags mode). If ** is specified as '``-``', then the tags are written to standard output instead. ctags will stubbornly refuse to take orders if tagfile exists and its first line contains something other than a valid tags line. This will save your neck if you mistakenly type "``ctags -f *.c``", which would otherwise overwrite your first C file with the tags generated by the rest! It will also refuse to accept a multi-character file name which begins with a '``-``' (dash) character, since this most likely means that you left out the tag file name and this option tried to grab the next option as the file name. If you really want to name your output tag file ``-ugly``, specify it as "``-f ./-ugly``". This option must appear before the first file name. If this option is specified more than once, only the last will apply. ``-o `` Equivalent to "``-f tagfile``". .. _option_output_format: Output Format Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``--format=(1|2)`` Change the format of the output tag file. Currently the only valid values for level are 1 or 2. Level 1 specifies the original tag file format and level 2 specifies a new extended format containing extension fields (but in a manner which retains backward-compatibility with original ``vi(1)`` implementations). The default level is 2. [Ignored in etags mode] ``--output-format=(u-ctags|e-ctags|etags|xref|json)`` Specify the output format. The default is ``u-ctags``. See :ref:`tags(5) ` for ``u-ctags`` and ``e-ctags``. ``TAG_OUTPUT_MODE`` pseudo tag indicates the choice, ``u-ctags`` or ``e-ctags``. See :ref:`ctags-client-tools(7) ` for more about the pseudo tag. See ``-e`` for ``etags``, and ``-x`` for ``xref``. ``json`` format is available only if the ctags executable is built with ``libjansson``. See :ref:`ctags-json-output(5) ` for more about ``json`` format. See also ``--list-output-formats``. ``-e`` Same as ``--output-format=etags``. Enable etags mode, which will create a tag file for use with the Emacs editor. Alternatively, if ctags is invoked by a name containing the string "etags" (either by renaming, or creating a link to, the executable), etags mode will be enabled. ``-x`` Same as ``--output-format=xref``. Print a tabular, human-readable cross reference (xref) file to standard output instead of generating a tag file. The information contained in the output includes: the tag name; the kind of tag; the line number, file name, and source line (with extra white space condensed) of the file which defines the tag. No tag file is written and all options affecting tag file output will be ignored. Example applications for this feature are generating a listing of all functions located in a source file (e.g. "``ctags -x --kinds-c=f file``"), or generating a list of all externally visible global variables located in a source file (e.g. "``ctags -x --kinds-c=v --extras=-F file``"). ``--sort=(yes|no|foldcase)`` Indicates whether the tag file should be sorted on the tag name (default is ``yes``). Note that the original ``vi(1)`` required sorted tags. The ``foldcase`` value specifies case insensitive (or case-folded) sorting. Fast binary searches of tag files sorted with case-folding will require special support from tools using tag files, such as that found in the ctags readtags library, or Vim version 6.2 or higher (using "``set ignorecase``"). [Ignored in etags mode] ``-u`` Equivalent to ``--sort=no`` (i.e. "unsorted"). ``--etags-include=`` Include a reference to ** in the tag file. This option may be specified as many times as desired. This supports Emacs' capability to use a tag file which *includes* other tag files. [Available only in etags mode] ``--input-encoding=`` Specifies the ** of the input files. If this option is specified, Universal Ctags converts the input from this encoding to the encoding specified by ``--output-encoding=encoding``. ``--input-encoding-=`` Specifies a specific input ** for **. It overrides the global default value given with ``--input-encoding``. ``--output-encoding=`` Specifies the ** of the tags file. Universal Ctags converts the encoding of input files from the encoding specified by ``--input-encoding=`` to this encoding. In addition ** is specified at the top the tags file as the value for the ``TAG_FILE_ENCODING`` pseudo-tag. The default value of ** is ``UTF-8``. .. _option_lang_mapping: Language Selection and Mapping Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``--language-force=(|auto)`` By default, ctags automatically selects the language of a source file, ignoring those files whose language cannot be determined (see "`Determining file language`_"). This option forces the specified *language* (case-insensitive; either built-in or user-defined) to be used for every supplied file instead of automatically selecting the language based upon its extension. In addition, the special value ``auto`` indicates that the language should be automatically selected (which effectively disables this option). ``--languages=[+|-](|all)`` Specifies the languages for which tag generation is enabled, with ** containing a comma-separated list of language names (case-insensitive; either built-in or user-defined). If the first language of ** is not preceded by either a '``+``' or '``-``', the current list (the current settings of enabled/disabled languages managed in ctags internally) will be cleared before adding or removing the languages in **. Until a '``-``' is encountered, each language in the ** will be added to the current list. As either the '``+``' or '``-``' is encountered in the **, the languages following it are added or removed from the current list, respectively. Thus, it becomes simple to replace the current list with a new one, or to add or remove languages from the current list. The actual list of files for which tags will be generated depends upon the language extension mapping in effect (see the ``--langmap`` option). Note that the most of languages, including user-defined languages, are enabled unless explicitly disabled using this option. Language names included in list may be any built-in language or one previously defined with ``--langdef``. The default is ``all``, which is also accepted as a valid argument. See the ``--list-languages`` option for a list of the all (built-in and user-defined) language names. Note ``--languages=`` option works cumulative way; the option can be specified with different arguments multiple times in a command line. ``--alias-=[+|-](|default)`` Adds ('``+``') or removes ('``-``') an alias ** to a language specified with **. ctags refers to the alias pattern in "`Determining file language`_" stage. The parameter ** is not a list. Use this option multiple times in a command line to add or remove multiple alias patterns. To restore the default language aliases, specify ``default``. Using ``all`` for ** has meaning in following two cases: ``--alias-all=`` This clears aliases setting of all languages. ``--alias-all=default`` This restores the default languages aliases for all languages. ``--guess-language-eagerly`` Looks into the file contents for heuristically guessing the proper language parser. See "`Determining file language`_". ``-G`` Equivalent to ``--guess-language-eagerly``. ``--langmap=[,[...]]`` Controls how file names are mapped to languages (see the ``--list-maps`` option). Each comma-separated ** consists of the language name (either a built-in or user-defined language), a colon, and a list of *file extensions* and/or *file name patterns*. A file extension is specified by preceding the extension with a period (e.g. ``.c``). A file name pattern is specified by enclosing the pattern in parentheses (e.g. ``([Mm]akefile)``). If appropriate support is available from the runtime library of your C compiler, then the file name pattern may contain the usual shell wildcards common on Unix (be sure to quote the option parameter to protect the wildcards from being expanded by the shell before being passed to ctags). You can determine if shell wildcards are available on your platform by examining the output of the ``--list-features`` option, which will include ``wildcards`` in the compiled feature list; otherwise, the file name patterns are matched against file names using a simple textual comparison. When mapping a file extension or a file name pattern with ``--langmap`` option, it will first be unmapped from any other languages. (``--map-`` option provides more fine-grained control.) If the first character in a ** is a plus sign ('``+``'), then the extensions and file name patterns in that map will be appended to the current map for that language; otherwise, the map will replace the current map. For example, to specify that only files with extensions of ``.c`` and ``.x`` are to be treated as C language files, use ``--langmap=c:.c.x``; to also add files with extensions of ``.j`` as Java language files, specify ``--langmap=c:.c.x,java:+.j``. To map makefiles (e.g. files named either ``Makefile``, ``makefile``, or having the extension ``.mak``) to a language called ``make``, specify ``--langmap=make:([Mm]akefile).mak``. To map files having no extension, specify a period not followed by a non-period character (e.g. '``.``', ``..x``, ``.x.``). To clear the mapping for a particular language (thus inhibiting automatic generation of tags for that language), specify an empty extension list (e.g. ``--langmap=fortran:``). To restore the default language mappings for a particular language, supply the keyword ``default`` for the mapping. To specify restore the default language mappings for all languages, specify ``--langmap=default``. Note that file name patterns are tested before file extensions when inferring the language of a file. This order of Universal Ctags is different from Exuberant Ctags. See :ref:`ctags-incompatibilities(7) ` for the background of this incompatible change. Unlike ``--map-`` option, you cannot specify relative-path regular expressions to ``--langmap`` option. ``--map-=[+|-]||`` This option provides the way to control mapping(s) of file names to languages in a more fine-grained way than ``--langmap`` option. In ctags, more than one language can map to a relative-path regular expression (**), file name **, or file ** (*N:1 map*). Alternatively, ``--langmap`` option handle only *1:1 map*, only one language mapping to one file name ** or file **. A typical N:1 map is seen in C++ and ObjectiveC language; both languages have a map to ``.h`` as a file extension. A file extension is specified by preceding the extension with a period (e.g. ``.c``). A file name pattern is specified by enclosing the pattern in parentheses (e.g. ``([Mm]akefile)``). A relative-path regular expression is specified by enclosing the expressions in percent signs '``%``' (e.g. ``%include/.*\.h%``). To include a literal percent sign inside the regular expression, escape it as ``\%``. A prefixed plus ('``+``') sign is for adding, and minus ('``-``') is for removing. No prefix means replacing the map of **. Unlike ``--langmap``, ``--map-`` does not take a list; ``--map-`` takes one extension, one pattern, or one regular expression. However, the option can be specified with different arguments multiple times in a command line. For file extensions and file name patterns, the match is performed with a base file name, a file without any directory components. For relative-path regular expressions, the match is performed with a relative-path incorporating the directory components. A relative-path is relative to the directory where ctags launches. Assume your shell is in ``/project/x`` directory and you have the following source tree under the directory. .. code-block:: src └── lib ├── data.c └── logic.c If you run ctags with ``ctags -R src``, the match is performed with ``src/lib/data.c`` and ``src/lib/logic.c`` If you give ``--map-YourParser='%src/lib/.*\.c%'``, ctags chooses ``YourParser`` parser for processing ``data.c`` and ``logic.c`` in the tree. If your shell is in ``/project/x/src`` and you run ``ctags -R lib``, ctags may not choose ``YourParser`` because the match is performed with ``lib/data.c`` and ``lib/logic.c``. A relative-path regular expression can take a flag controlling its testing. The flag comes after the last percent sign. Currently only one available flag: ``{icase}`` (one-letter form '``i``') The regular expression is to be applied in a case-insensitive manner. (e.g. ``%include/.*\.h%i`` or ``%include/.*\.h%{icase}`` The relative-path regular expression is available since version 6.3.0. .. _option_tags_file_contents: Tags File Contents Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See "`TAG ENTRIES`_" about fields, kinds, roles, and extras. ``--excmd=(number|pattern|mix|combine)`` Determines the type of ``EX`` command used to locate tags in the source file. [Ignored in etags mode] The valid values for type (either the entire word or the first letter is accepted) are: ``number`` Use only line numbers in the tag file for locating tags. This has four advantages: 1. Significantly reduces the size of the resulting tag file. 2. Eliminates failures to find tags because the line defining the tag has changed, causing the pattern match to fail (note that some editors, such as ``vim``, are able to recover in many such instances). 3. Eliminates finding identical matching, but incorrect, source lines (see "`BUGS`_"). 4. Retains separate entries in the tag file for lines which are identical in content. In pattern mode, duplicate entries are dropped because the search patterns they generate are identical, making the duplicate entries useless. However, this option has one significant drawback: changes to the source files can cause the line numbers recorded in the tag file to no longer correspond to the lines in the source file, causing jumps to some tags to miss the target definition by one or more lines. Basically, this option is best used when the source code to which it is applied is not subject to change. Selecting this option type causes the following options to be ignored: ``-B``, ``-F``. ``number`` type is ignored in Xref and JSON output formats. Use ``--_xformat="...%n"`` for Xref output format, or ``--fields=+n-P`` for JSON output format. .. NOTE: #2792 ``pattern`` Use only search patterns for all tags, rather than the line numbers usually used for macro definitions. This has the advantage of not referencing obsolete line numbers when lines have been added or removed since the tag file was generated. ``mixed`` In this mode, patterns are generally used with an exceptions. For Fortran, line numbers are used for common blocks because their corresponding source lines are generally identical, making pattern searches useless for finding all matches. Exuberant Ctags has one more exception; for C, line numbers are used for macro definition tags. Universal Ctags doesn't have this exception for C. This was the default format generated by the original ctags and is, therefore, retained as the default for this option. ``combine`` Concatenate the line number and pattern with a semicolon in between. ``-n`` Equivalent to ``--excmd=number``. ``-N`` Equivalent to ``--excmd=pattern``. ``--extras=[+|-][|*]`` Specifies whether to include extra tag entries for certain kinds of information. See also "`Extras`_" subsection to know what are extras. The parameter ** is a set of one-letter flags (and/or long-name flags), each representing one kind of extra tag entry to include in the tag file. If flags is preceded by either the '``+``' or '``-``' character, the effect of each flag is added to, or removed from, those currently enabled; otherwise the flags replace any current settings. All entries are included if '``*``' is given. This ``--extras=`` option is for controlling extras common in all languages (or language-independent extras). Universal Ctags also supports language-specific extras. (See "`Language-specific fields and extras`_" about the concept). Use ``--extras-=`` option for controlling them. ``--extras-(|all)=[+|-][|*]`` Specifies whether to include extra tag entries for certain kinds of information for language **. Universal Ctags introduces language-specific extras. See "`Language-specific fields and extras`_" about the concept. This option is for controlling them. Specifies ``all`` as ** to apply the parameter ** to all languages; all extras are enabled with specifying '``*``' as the parameter flags. If specifying nothing as the parameter flags (``--extras-all=``), all extras are disabled. These two combinations are useful for testing. Check the output of the ``--list-extras=`` option for the extras of specific language **. ``--fields=[+|-][|*]`` Specifies which language-independent fields are to be included in the tag entries. Language-independent fields are extension fields which are common in all languages. See "`TAG FILE FORMAT`_" section, and "`Extension fields`_" subsection, for details of extension fields. The parameter ** is a set of one-letter or long-name flags, each representing one type of extension field to include. Each flag or group of flags may be preceded by either '``+``' to add it to the default set, or '``-``' to exclude it. In the absence of any preceding '``+``' or '``-``' sign, only those fields explicitly listed in flags will be included in the output (i.e. overriding the default set). All fields are included if '``*``' is given. This option is ignored if the option ``--format=1`` (legacy tag file format) has been specified. Use ``--fields-=`` option for controlling language-specific fields. ``--fields-(|all)=[+|-][|*]`` Specifies which language-specific fields are to be included in the tag entries. Universal Ctags supports language-specific fields. (See "`Language-specific fields and extras`_" about the concept). Specify ``all`` as ** to apply the parameter ** to all languages; all fields are enabled with specifying '``*``' as the parameter flags. If specifying nothing as the parameter ** (i.e. ``--fields-all=``), all fields are disabled. These two combinations are useful for testing. See the description of ``--fields=[+|-][|*]`` about **. Use ``--fields=`` option for controlling language-independent fields. ``--kinds-(|all)=[+|-](|*)`` Specifies a list of language-specific ** of tags (or kinds) to include in the output file for a particular language, where ** is case-insensitive and is one of the built-in language names (see the ``--list-languages`` option for a complete list). The parameter ** is a group of one-letter or long-name flags designating kinds of tags (particular to the language) to either include or exclude from the output. The specific sets of flags recognized for each language, their meanings and defaults may be list using the ``--list-kinds-full`` option. Each letter or group of letters may be preceded by either '``+``' to add it to, or '``-``' to remove it from, the default set. In the absence of any preceding '``+``' or '``-``' sign, only those kinds explicitly listed in kinds will be included in the output (i.e. overriding the default for the specified language). Specify '``*``' as the parameter to include all kinds implemented in ** in the output. Furthermore if ``all`` is given as **, specification of the parameter ``kinds`` affects all languages defined in ctags. Giving ``all`` makes sense only when '``*``' or '``F``' is given as the parameter ``kinds``. As an example for the C language, in order to add prototypes and external variable declarations to the default set of tag kinds, but exclude macros, use ``--kinds-c=+px-d``; to include only tags for functions, use ``--kinds-c=f``. Some kinds of C and C++ languages are synchronized; enabling (or disabling) a kind in one language enables the kind having the same one-letter and long-name in the other language. See also the description of ``MASTER`` column of ``--list-kinds-full``. .. COMMENT: ``--param-.name=argument`` is moved to "Language Specific Options" ``--pattern-length-limit=`` Truncate patterns of tag entries after ** characters. Disable by setting to 0 (default is 96). An input source file with long lines and multiple tag matches per line can generate an excessively large tags file with an unconstrained pattern length. For example, running ctags on a minified JavaScript source file often exhibits this behavior. The truncation avoids cutting in the middle of a UTF-8 code point spanning multiple bytes to prevent writing invalid byte sequences from valid input files. This handling allows for an extra 3 bytes above the configured limit in the worse case of a 4 byte code point starting right before the limit. Please also note that this handling is fairly naive and fast, and although it is resistant against any input, it requires a valid input to work properly; it is not guaranteed to work as the user expects when dealing with partially invalid UTF-8 input. This also partially affect non-UTF-8 input, if the byte sequence at the truncation length looks like a multibyte UTF-8 sequence. This should however be rare, and in the worse case will lead to including up to an extra 3 bytes above the limit. ``--pseudo-tags=[+|-](|*)`` Enable/disable emitting pseudo-tag named **. If '``*``' is given, enable/disable emitting all pseudo-tags. ``--put-field-prefix`` Put ``UCTAGS`` as prefix for the name of fields newly introduced in Universal Ctags. Some fields are newly introduced in Universal Ctags and more will be introduced in the future. Other tags generators may also introduce their specific fields. In such a situation, there is a concern about conflicting field names; mixing tags files generated by multiple tags generators including Universal Ctags is difficult. This option provides a workaround for such station. .. code-block:: console $ ctags --fields='{line}{end}' -o - hello.c main hello.c /^main(int argc, char **argv)$/;" f line:3 end:6 $ ctags --put-field-prefix --fields='{line}{end}' -o - hello.c main hello.c /^main(int argc, char **argv)$/;" f line:3 UCTAGSend:6 In the above example, the prefix is put to ``end`` field which is newly introduced in Universal Ctags. ``--roles-(|all).(|*)=[+|-][|*]`` Specifies a list of kind-specific roles of tags to include in the output file for a particular language. ** specifies the kind where the ** are defined. ** specifies the language where the kind is defined. Each role in ** must be surrounded by braces (e.g. ``{system}`` for a role named "system"). Like ``--kinds-`` option, '``+``' is for adding the role to the list, and '``-``' is for removing from the list. '``*``' is for including all roles of the kind to the list. The option with no argument makes the list empty. Both a one-letter flag or a long name flag surrounded by braces are acceptable for specifying a kind (e.g. ``--roles-C.h=+{system}{local}`` or ``--roles-C.{header}=+{system}{local}``). '``*``' can be used for ** only for adding/removing all roles of all kinds in a language to/from the list (e.g. ``--roles-C.*=*`` or ``--roles-C.*=``). ``all`` can be used for ** only for adding/removing all roles of all kinds in all languages to/from the list (e.g. ``--roles-all.*=*`` or ``--roles-all.*=``). ``--tag-relative=(yes|no|always|never)`` Specifies how the file paths recorded in the tag file. The default is ``yes`` when running in etags mode (see the ``-e`` option), ``no`` otherwise. ``yes`` indicates that the file paths recorded in the tag file should be *relative to the directory containing the tag file* unless the files supplied on the command line are specified with absolute paths. ``no`` indicates that the file paths recorded in the tag file should be *relative to the current directory* unless the files supplied on the command line are specified with absolute paths. ``always`` indicates the recorded file paths should be relative even if source file names are passed in with absolute paths. ``never`` indicates the recorded file paths should be absolute even if source file names are passed in with relative paths. ``--use-slash-as-filename-separator[=(yes|no)]`` Uses slash ('``/``') character as filename separators instead of backslash ('``\``') character when printing ``input:`` field. The default is ``yes`` for the default "u-ctags" output format, and ``no`` for the other formats. ``TAG_OUTPUT_FILESEP`` pseudo tag is for representing the choice of filename separators with this option. See also :ref:`ctags-client-tools(7) `. This option is available on MS Windows only. ``-B`` Use backward searching patterns (e.g. ``?pattern?``). [Ignored in etags mode] ``-F`` Use forward searching patterns (e.g. ``/pattern/``) (default). [Ignored in etags mode] Option File Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. TODO: merge some of description in option-file.rst into FILE or a dedicated section ``--options=`` Read additional options from file or directory. ctags searches ** in the optlib path list first. If ctags cannot find a file or directory in the list, ctags reads a file or directory at the specified **. If a file is specified, it should contain one option per line. If a directory is specified, files suffixed with ``.ctags`` under it are read in alphabetical order. As a special case, if ``--options=NONE`` is specified as the first option on the command line, preloading is disabled; the option will disable the automatic reading of any configuration options from a file (see "`FILES`_"). ``--options-maybe=`` Same as ``--options`` but doesn't cause an error if file (or directory) specified with ** doesn't exist. ``--optlib-dir=[+]`` Add an optlib ** to or reset the optlib path list. See "`Default optlib path list`_" about the default elements for optlib path list. optlib Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`ctags-optlib(7) ` for details of each option. ``--kinddef-=,,`` Define a kind for **. Don't be confused this with ``--kinds-``. ``--langdef=`` Defines a new user-defined language, **, to be parsed with regular expressions. ``--mline-regex-=////[]`` Define multi-line regular expression for locating tags in specific language. ``--regex-=////[]`` Define single-line regular expression for locating tags in specific language. .. _option_lang_specific: Language Specific Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``--if0[=(yes|no)]`` Indicates a preference as to whether code within an "``#if 0``" branch of a preprocessor conditional should be examined for non-macro tags (macro tags are always included). Because the intent of this construct is to disable code, the default value of this option is ``no`` (disabled). Note that this indicates a preference only and does not guarantee skipping code within an "``#if 0``" branch, since the fall-back algorithm used to generate tags when preprocessor conditionals are too complex follows all branches of a conditional. ``--line-directives[=(yes|no)]`` Specifies whether ``#line`` directives should be recognized. These are present in the output of a preprocessor and contain the line number, and possibly the file name, of the original source file(s) from which the preprocessor output file was generated. This option is off by default. When enabled, this option will cause ctags to generate tag entries marked with the file names and line numbers of their locations original source file(s), instead of their actual locations in the preprocessor output. The actual file names placed into the tag file will have the same leading path components as the preprocessor output file, since it is assumed that the original source files are located relative to the preprocessor output file (unless, of course, the ``#line`` directive specifies an absolute path). Note: This option is generally only useful when used together with the ``--excmd=number`` (``-n``) option. Also, you may have to use either the ``--langmap`` or ``--language-force`` option if the extension of the preprocessor output file is not known to ctags. ``-D =`` Defines a C preprocessor **. This emulates the behavior of the corresponding gcc option. All types of macros are supported, including the ones with parameters and variable arguments. Stringification, token pasting and recursive macro expansion are also supported. This extends the function provided by ``-I`` option. ``-h (|default)`` Specifies a ** of file extensions, separated by periods, which are to be interpreted as include (or header) files. To indicate files having no extension, use a period not followed by a non-period character (e.g. '``.``', ``..x``, ``.x.``). This option only affects how the scoping of particular kinds of tags are interpreted (i.e. whether or not they are considered as globally visible or visible only within the file in which they are defined); it does not map the extension to any particular language. Any tag which is located in a non-include file and cannot be seen (e.g. linked to) from another file is considered to have file-limited (e.g. static) scope. No kind of tag appearing in an include file will be considered to have file-limited scope. If the first character in the list is '``+``', then the extensions in the list will be appended to the current list; otherwise, the list will replace the current list. See, also, the ``fileScope``/``F`` flag of ``--extras`` option. The default list is ``.h.H.hh.hpp.hxx.h++.inc.def``. To restore the default list, specify "``-h default``". Note that if an extension supplied to this option is not already mapped to a particular language (see "`Determining file language`_", above), you will also need to use either the ``--map-``, ``--langmap`` or ``--language-force`` option. ``-I `` Specifies a ** of identifiers which are to be specially handled while parsing C and C++ source files. This option is specifically provided to handle special cases arising through the use of preprocessor macros. When the identifiers listed are simple identifiers, these identifiers will be ignored during parsing of the source files. If an identifier is suffixed with a '``+``' character (i.e. "``-I FOO+``"), ctags will also ignore any parenthesis-enclosed argument list which may immediately follow the identifier in the source files. See the example of "``-I MODULE_VERSION+``" below. If two identifiers are separated with the '``=``' character (i.e. ``-I FOO=BAR``), the first identifiers is replaced by the second identifiers for parsing purposes. The list of identifiers may be supplied directly on the command line or read in from a separate file. See the example of "``-I CLASS=class``" below. If the first character of ** is '``@``', '``.``' or a pathname separator ('``/``' or '``\``'), or the first two characters specify a drive letter (e.g. ``C:``), the parameter ** will be interpreted as a filename from which to read a list of identifiers, one per input line. Otherwise, ** is a list of identifiers (or identifier pairs) to be specially handled, each delimited by either a comma or by white space (in which case the list should be quoted to keep the entire list as one command line argument). Multiple ``-I`` options may be supplied. To clear the list of ignore identifiers, supply a single dash ('``-``') for **. This feature is useful when preprocessor macros are used in such a way that they cause syntactic confusion due to their presence. Indeed, this is the best way of working around a number of problems caused by the presence of syntax-busting macros in source files (see "`CAVEATS`_"). Some examples will illustrate this point. .. code-block:: C int foo ARGDECL4(void *, ptr, long int, nbytes) In the above example, the macro ``ARGDECL4`` would be mistakenly interpreted to be the name of the function instead of the correct name of ``foo``. Specifying "``-I ARGDECL4``" results in the correct behavior. .. code-block:: C /* creates an RCS version string in module */ MODULE_VERSION("$Revision$") In the above example the macro invocation looks too much like a function definition because it is not followed by a semicolon (indeed, it could even be followed by a global variable definition that would look much like a K&R style function parameter declaration). In fact, this seeming function definition could possibly even cause the rest of the file to be skipped over while trying to complete the definition. Specifying "``-I MODULE_VERSION+``" would avoid such a problem. .. code-block:: C CLASS Example { // your content here }; The example above uses ``CLASS`` as a preprocessor macro which expands to something different for each platform. For instance ``CLASS`` may be defined as ``class __declspec(dllexport)`` on Win32 platforms and simply ``class`` on UNIX. Normally, the absence of the C++ keyword ``class`` would cause the source file to be incorrectly parsed. Correct behavior can be restored by specifying "``-I CLASS=class``". ``--param-.=`` Set a ** specific parameter, a parameter specific to the **. Available parameters can be listed with ``--list-params``. .. _option_listing: Listing Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``--list-aliases[=(|all)]`` Lists the aliases for either the specified ** or ``all`` languages, and then exits. ``all`` is used as default value if the option argument is omitted. The aliases are used when heuristically testing a language parser for a source file. ``--list-excludes`` Lists the current exclusion patterns used to exclude files. ``--list-extras[=(|NONE|all)]`` Lists the extras recognized for either the specified ** or ``all`` languages. If ``NONE`` is specified, it lists only extras common in all languages. See "`Extras`_" subsection to know what are extras. ``all`` is used as default value if the option argument is omitted. An extra can be enabled or disabled with ``--extras=`` for common extras in all languages, or ``--extras-=`` for the specified language. These option takes one-letter flag or long-name flag as a parameter for specifying an extra. The meaning of columns in output are as follows: LETTER One-letter flag. '``-``' means the extra does not have one-letter flag. NAME Long-name flag. The long-name is used in ``extras`` field. ENABLED Whether the extra is enabled or not. It takes ``yes`` or ``no``. LANGUAGE The name of language if the extra is owned by a parser. ``NONE`` means the extra is common in parsers. VER The ctags output version introducing the extra for a language-independent extra, or the parser version introducing the extra for a language-specified extra. See the ``--version`` option and ``TAG_OUTPUT_VERSION`` in :ref:`ctags-client-tools(7) ` about the ctags output version. (since version 6.3.0) DESCRIPTION Human readable description for the extra. ``--list-features`` Lists the compiled features. ``--list-fields[=(|NONE|all)]`` Lists the fields recognized for either the specified ** or ``all`` languages. If ``NONE`` is specified, it lists only fields common in all languages. See "`Extension fields`_" subsection to know what are fields. ``all`` is used as default value if the option argument is omitted. The meaning of columns are as follows: LETTER One-letter flag. '``-``' means the field does not have one-letter flag. NAME Long-name of field. ENABLED Whether the field is enabled or not. It takes ``yes`` or ``no``. LANGUAGE The name of language if the field is owned by a parser. ``NONE`` means that the field is a language-independent field which is common in all languages. JSTYPE JSON type used in printing the value of field when ``--output-format=json`` is specified. See :ref:`ctags-client-tools(7) `. FIXED Whether this field can be disabled or not in tags output. Some fields are printed always in tags output. They have ``yes`` as the value for this column. Unlike the tag output mode, JSON output mode allows disabling any fields. OP How this field can be accessed from optscript code. This field is for Universal Ctags developers. VER The ctags output version introducing the field for a language-independent field, or the parser version introducing the field for a language-specified field. See the ``--version`` option and ``TAG_OUTPUT_VERSION`` in :ref:`ctags-client-tools(7) ` about the ctags output version. (since version 6.3.0) DESCRIPTION Human readable description for the field. ``--list-kinds[=(|all)]`` Subset of ``--list-kinds-full``. This option is kept for backward-compatibility with Exuberant Ctags. This option prints only LETTER, DESCRIPTION, and ENABLED fields of ``--list-kinds-full`` output. However, the presentation of ENABLED column is different from that of ``--list-kinds-full`` option; ``[off]`` follows after description if the kind is disabled, and nothing follows if enabled. The most of all kinds are enabled by default. The critical weakness of this option is that this option does not print the name of kind. Universal Ctags introduces ``--list-kinds-full`` because it considers that names are important. This option does not work with ``--machinable`` nor ``--with-list-header``. ``--list-kinds-full[=(|all)]`` Lists the tag kinds recognized for either the specified ** or ``all`` languages, and then exits. See "`Kinds`_" subsection to learn what kinds are. ``all`` is used as default value if the option argument is omitted. Each kind of tag recorded in the tag file is represented by a one-letter flag, or a long-name flag. They are also used to filter the tags placed into the output through use of the ``--kinds-`` option. The meaning of columns are as follows: LANGUAGE The name of language having the kind. LETTER One-letter flag. This must be unique in a language. NAME The long-name flag of the kind. This can be used as the alternative to the one-letter flag described above. If enabling ``K`` field with ``--fields=+K``, ctags uses long-names instead of one-letters in tags output. To enable/disable a kind with ``--kinds-`` option, long-name surrounded by braces instead of one-letter. See "`Letters and names`_" for details. This must be unique in a language. ENABLED Whether the kind is enabled or not. It takes ``yes`` or ``no``. REFONLY Whether the kind is specialized for reference tagging or not. If the column is ``yes``, the kind is for reference tagging, and it is never used for definition tagging. See also "`TAG ENTRIES`_". NROLES The number of roles this kind has. See also "`Roles`_". MASTER The master parser controlling enablement of the kind. A kind belongs to a language (owner) in Universal Ctags; enabling and disabling a kind in a language has no effect on a kind in another language even if both kinds has the same one-letter flag and/or the same long-name flag. In other words, the namespace of kinds are separated by language. However, Exuberant Ctags does not separate the kinds of C and C++. Enabling/disabling kindX in C language enables/disables a kind in C++ language having the same long-name flag with kindX. To emulate this behavior in Universal Ctags, a concept named *master parser* is introduced. Enabling/disabling some kinds are synchronized under the control of a master language. .. code-block:: console $ ctags --kinds-C=+'{local}' --list-kinds-full \ | grep -E '^(#|C\+\+ .* local)' #LANGUAGE LETTER NAME ENABLED REFONLY NROLES MASTER DESCRIPTION C++ l local yes no 0 C local variables $ ctags --kinds-C=-'{local}' --list-kinds-full \ | grep -E '^(#|C\+\+ .* local)' #LANGUAGE LETTER NAME ENABLED REFONLY NROLES MASTER DESCRIPTION C++ l local no no 0 C local variables You see ``ENABLED`` field of ``local`` kind of C++ language is changed Though ``local`` kind of C language is enabled/disabled. If you swap the languages, you see the same result. .. TODO: need a reference to "master parser" VER The parser version introducing the kind. (since version 6.3.0) DESCRIPTION Human readable description for the kind. ``--list-languages`` Lists the names of the languages understood by ctags, and then exits. These language names are case insensitive and may be used in many other options like ``--language-force``, ``--languages``, ``--kinds-``, ``--regex-``, and so on. Each language listed is disabled if followed by ``[disabled]``. To use the parser for such a language, specify the language as an argument of ``--languages=+`` option. ``--machinable`` and ``--with-list-header`` options are ignored if they are specified with this option. ``--list-map-extensions[=(|all)]`` Lists the file extensions which associate a file name with a language for either the specified ** or ``all`` languages, and then exits. ``all`` is used as default value if the option argument is omitted. ``--list-map-patterns[=(|all)]`` Lists the file name patterns which associate a file name with a language for either the specified ** or ``all`` languages, and then exits. ``all`` is used as default value if the option argument is omitted. ``--list-map-rexprs[=(|all)]`` Lists the relative-path regular expressions which associate a file name with a language for either the specified ** or ``all`` languages, and then exits. ``all`` is used as default value if the option argument is omitted. (since version 6.3.0) ``--list-maps[=(|all)]`` Lists the file name patterns, the file extensions, and the relative-path regular expressions which associate a file name with a language for either the specified ** or ``all`` languages, and then exits. ``all`` is used as default value if the option argument is omitted. To list the file extensions, file name patterns, or relative-path regular expressions individually, use ``--list-map-extensions``, ``--list-map-patterns``, or ``--list-map-rexprs`` option. See the ``--langmap`` option, and "`Determining file language`_", above. This option does not work with ``--machinable`` nor ``--with-list-header``. ``--list-mline-regex-flags`` Output list of flags which can be used in a multiline regex parser definition. See :ref:`ctags-optlib(7) `. ``--list-output-formats`` Lists the output formats that can be used in ``--output-format`` option. ``NULLTAG`` column represetns whether the format supports *null tags* or not. See ``nulltag``/``z`` in "`Extras`_" about the null tags. (since version 6.2.0) ``--list-params[=(|all)]`` Lists the parameters for either the specified ** or ``all`` languages, and then exits. ``all`` is used as default value if the option argument is omitted. ``--list-pseudo-tags`` Output list of pseudo-tags. ``--list-regex-flags`` Lists the flags that can be used in ``--regex-`` option. See :ref:`ctags-optlib(7) `. ``--list-roles[=(|all)[.(|*)]]`` List the roles for either the specified ** or ``all`` languages. ``all`` is used as default value if the option argument is omitted. If the parameter ** is given after the parameter ** or ``all`` with concatenating with '``.``', list only roles defined in the kinds. Both one-letter flags and long name flags surrounded by braces are acceptable as the parameter **. The meaning of columns are as follows: LANGUAGE The name of language having the role. KIND(L/N) The one-letter flag and the long-name flag of kind having the role. NAME The long-name flag of the role. ENABLED Whether the kind is enabled or not. It takes ``yes`` or ``no``. VER The parser version introducing the role. (since version 6.3.0) DESCRIPTION Human readable description for the role. ``--list-subparsers[=(|all)]`` Lists the subparsers for a base language for either the specified ** or ``all`` languages, and then exits. ``all`` is used as default value if the option argument is omitted. ``--machinable[=(yes|no)]`` Use tab character as separators for ``--list-`` option output. It may be suitable for scripting. See "`List options`_" for considered use cases. Disabled by default. ``--with-list-header[=(yes|no)]`` Print headers describing columns in ``--list-`` option output. See also "`List options`_". .. _option_misc: Miscellaneous Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``--describe-language=`` Prints the various aspects of the parser implementing the language. (since version 6.3.0) ``--help`` Prints to standard output a detailed usage description, and then exits. ``-?`` Equivalent to ``--help``. ``--help-full`` Prints to standard output a detailed usage description including experimental features, and then exits. Visit https://docs.ctags.io/ for information about the latest exciting experimental features. ``--license`` Prints a summary of the software license to standard output, and then exits. ``--print-language`` Just prints the language parsers for specified source files, and then exits. ``--quiet[=(yes|no)]`` Write fewer messages (default is ``no``). ``--totals[=(yes|no|extra)]`` Prints statistics about the source files read and the tag file written during the current invocation of ctags. This option is ``no`` by default. The ``extra`` value prints parser specific statistics for parsers gathering such information. ``--verbose[=(yes|no)]`` Enable verbose mode. This prints out information on option processing and a brief message describing what action is being taken for each file considered by ctags. Normally, ctags does not read command line arguments until after options are read from the configuration files (see "`FILES`_", below). However, if this option is the first argument on the command line, it will take effect before any options are read from these sources. The default is ``no``. ``-V`` Equivalent to ``--verbose``. ``--version[=|NONE]`` Prints a version identifier for ctags to standard output, and then exits. This is guaranteed to always contain the string "Universal Ctags". See also the description for ``TAG_PROGRAM_VERSION`` and ``TAG_OUTPUT_VERSION`` in :ref:`ctags-client-tools(7) `. If ``NONE`` is given, prints the version identifier in a simplified way. If ** is given, print the version identifier for the parser for **. See also the description for ``TAG_PARSER_VERSION`` in :ref:`ctags-client-tools(7) `. Obsoleted Options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ These options are kept for backward-compatibility with Exuberant Ctags. ``-w`` This option is silently ignored for backward-compatibility with the ctags of SVR4 Unix. ``--file-scope[=(yes|no)]`` This options is removed. Use ``--extras=[+|-]F`` or ``--extras=[+|-]{fileScope}`` instead. ``--extra=[+|-][|*]`` Equivalent to ``--extras=[+|-][|*]``, which was introduced to make the option naming convention align to the other options like ``--kinds-=`` and ``--fields=``. ``---kinds=[+|-](|*)`` This option is obsolete. Use ``--kinds-=...`` instead. OPERATIONAL DETAILS ------------------- As ctags considers each source file name in turn, it tries to determine the language of the file by applying tests described in "`Determining file language`_". If a language was identified, the file is opened and then the appropriate language parser is called to operate on the currently open file. The parser parses through the file and adds an entry to the tag file for each language object it is written to handle. See "`TAG FILE FORMAT`_", below, for details on these entries. Notes for C/C++ Parser ~~~~~~~~~~~~~~~~~~~~~~~~~~ .. TODO: move the following description to parser-cxx.rst. This implementation of ctags imposes no formatting requirements on C code as do legacy implementations. Older implementations of ctags tended to rely upon certain formatting assumptions in order to help it resolve coding dilemmas caused by preprocessor conditionals. In general, ctags tries to be smart about conditional preprocessor directives. If a preprocessor conditional is encountered within a statement which defines a tag, ctags follows only the first branch of that conditional (except in the special case of ``#if 0``, in which case it follows only the last branch). The reason for this is that failing to pursue only one branch can result in ambiguous syntax, as in the following example: .. code-block:: C #ifdef TWO_ALTERNATIVES struct { #else union { #endif short a; long b; } Both branches cannot be followed, or braces become unbalanced and ctags would be unable to make sense of the syntax. If the application of this heuristic fails to properly parse a file, generally due to complicated and inconsistent pairing within the conditionals, ctags will retry the file using a different heuristic which does not selectively follow conditional preprocessor branches, but instead falls back to relying upon a closing brace ('``}``') in column 1 as indicating the end of a block once any brace imbalance results from following a ``#if`` conditional branch. ctags will also try to specially handle arguments lists enclosed in double sets of parentheses in order to accept the following conditional construct:: extern void foo __ARGS((int one, char two)); Any name immediately preceding the '``((``' will be automatically ignored and the previous name will be used. C++ operator definitions are specially handled. In order for consistency with all types of operators (overloaded and conversion), the operator name in the tag file will always be preceded by the string "operator " (i.e. even if the actual operator definition was written as "operator<<"). After creating or appending to the tag file, it is sorted by the tag name, removing identical tag lines. .. _guessing: Determining file language ~~~~~~~~~~~~~~~~~~~~~~~~~~ File name mapping .......................... Unless the ``--language-force`` option is specified, the language of each source file is automatically selected based upon a *mapping* of file names to languages. The mappings in effect for each language may be displayed using the ``--list-maps`` option and may be changed using the ``--langmap`` or ``--map-`` options. If the name of a file is not mapped to a language, ctags tries to heuristically guess the language for the file by inspecting its content. All files that have no file name mapping and no guessed parser are ignored. This permits running ctags on all files in either a single directory (e.g. "``ctags *``"), or on all files in an entire source directory tree (e.g. "``ctags -R``"), since only those files whose names are mapped to languages will be scanned. An extension may be mapped to multiple parsers. For example, ``.h`` are mapped to C++, C and ObjectiveC. These mappings can cause issues. ctags tries to select the proper parser for the source file by applying heuristics to its content, however it is not perfect. In case of issues one can use ``--language-force=``, ``--langmap=[,[...]]``, or the ``--map-=[+|-]||`` options. (Some of the heuristics are applied whether ``--guess-language-eagerly`` is given or not.) The order of testing is relative-path regular expressions (specified with ``--map-=``), file name patterns, then file extensions. .. TODO: all heuristics??? To be confirmed. Heuristically guessing .......................... If ctags cannot select a parser from the mapping of file names, various heuristic tests are conducted to determine the language: template file name testing If the file name has an ``.in`` extension, ctags applies the mapping to the file name without the extension. For example, ``config.h`` is tested for a file named ``config.h.in``. "interpreter" testing The first line of the file is checked to see if the file is a ``#!`` script for a recognized language. ctags looks for a parser having the same name. If ctags finds no such parser, ctags looks for the name in alias lists. For example, consider if the first line is ``#!/bin/sh``. Though ctags has a "shell" parser, it doesn't have a "sh" parser. However, ``sh`` is listed as an alias for ``shell``, therefore ctags selects the "shell" parser for the file. An exception is ``env``. If ``env`` is specified (for example "``#!/usr/bin/env python``"), ctags reads more lines to find real interpreter specification. To display the list of aliases, use ``--list-aliases`` option. To add an item to the list or to remove an item from the list, use the ``--alias-=+`` or ``--alias-=-`` option respectively. "zsh autoload tag" testing If the first line starts with ``#compdef`` or ``#autoload``, ctags regards the line as "zsh". "emacs mode at the first line" testing The Emacs editor has multiple editing modes specialized for programming languages. Emacs can recognize a marker called modeline in a file and utilize the marker for the mode selection. This heuristic test does the same as what Emacs does. ctags treats ``MODE`` as a name of interpreter and applies the same rule of "interpreter" testing if the first line has one of the following patterns:: -*- mode: MODE -*- or :: -*- MODE -*- "emacs mode at the EOF" testing Emacs editor recognizes another marker at the end of file as a mode specifier. This heuristic test does the same as what Emacs does. ctags treats ``MODE`` as a name of an interpreter and applies the same rule of "interpreter" heuristic testing, if the lines at the tail of the file have the following pattern:: Local Variables: ... mode: MODE ... End: 3000 characters are sought from the end of file to find the pattern. "vim modeline" testing Like the modeline of the Emacs editor, Vim editor has the same concept. ctags treats ``TYPE`` as a name of interpreter and applies the same rule of "interpreter" heuristic testing if the first or last 5 lines of the file have one of the following patterns:: filetype=TYPE or :: ft=TYPE "PHP marker" testing If the first line is started with ``` and :ref:`ctags-client-tools(7) ` for more details. When not running in etags mode, each entry in the tag file consists of a separate line, each looking like this, called *regular tags*, in the most general case: :: ;" The fields and separators of these lines are specified as follows: 1. ````: tag name 2. ````: single tab character 3. ````: name of the file in which the object associated with the tag is located 4. ````: single tab character 5. ````: EX command used to locate the tag within the file; generally a search pattern (either ``/pattern/`` or ``?pattern?``) or line number (see ``--excmd=`` option). 6. ``;"``: a set of extension fields. See "`Extension fields`_" for more details. Tag file format 2 (see ``--format``) extends the EX command to include the extension fields embedded in an EX comment immediately appended to the EX command, which leaves it backward-compatible with original ``vi(1)`` implementations. A few special tags, called *pseudo tags*, are written into the tag file for internal purposes. :: !_TAG_FILE_FORMAT 2 /extended format; --format=1 will not append ;" to lines/ !_TAG_FILE_SORTED 1 /0=unsorted, 1=sorted, 2=foldcase/ ... ``--pseudo-tags=[+|-](|*)`` option enables or disables emitting pseudo-tags. See the output of "``ctags --list-pseudo-tags``" for the list of the kinds. See also :ref:`tags(5) ` and :ref:`ctags-client-tools(7) ` for more details of the pseudo tags. These tags are composed in such a way that they always sort to the top of the file. Therefore, the first two characters of these tags are used a magic number to detect a tag file for purposes of determining whether a valid tag file is being overwritten rather than a source file. Note that the name of each source file will be recorded in the tag file exactly as it appears on the command line. Therefore, if the path you specified on the command line was relative to the current directory, then it will be recorded in that same manner in the tag file. See, however, the ``--tag-relative=(yes|no|always|never)`` option for how this behavior can be modified. .. _tag_entries: TAG ENTRIES ----------- A tag is an index for a language object. The concept of a tag and related items in Exuberant Ctags are refined and extended in Universal Ctags. A tag is categorized into *definition tags* or *reference tags*. In general, Exuberant Ctags only tags *definitions* of language objects: places where newly named language objects *are introduced*. Universal Ctags, on the other hand, can also tag *references* of language objects: places where named language objects *are used*. However, support for generating reference tags is new and limited to specific areas of specific languages in the current version. Extension fields ~~~~~~~~~~~~~~~~ A tag can record various information, called *extension fields*. Extension fields are tab-separated key-value pairs appended to the end of the EX command as a comment, as described above. These key value pairs appear in the general form ``key:value``. In addition, information on the scope of the tag definition may be available, with the key portion equal to some language-dependent construct name and its value the name declared for that construct in the program. This scope entry indicates the scope in which the tag was found. For example, a tag generated for a C structure member would have a scope looking like ``struct:myStruct``. ``--fields=[+|-][|*]`` and ``--fields-(|all)=[+|-][|*]`` options specifies which available extension fields are to be included in the tag entries. See the output of "``ctags --list-fields``" for the list of extension fields. The essential fields are ``name``, ``input``, ``pattern``, and ``line``. The meaning of major fields is as follows (long-name flag/one-letter flag): ``access``/``a`` Indicates the visibility of this class member, where value is specific to the language. ``end``/``e`` Indicates the line number of the end lines of the language object. ``extras``/``E`` Extra tag type information. See "`Extras`_" for details. ``file``/``f`` Indicates that the tag has file-limited visibility. This key has no corresponding value. Enabled by default. ``implementation``/``m`` When present, this indicates a limited implementation (abstract vs. concrete) of a routine or class, where value is specific to the language (``virtual`` or ``pure virtual`` for C++; ``abstract`` for Java). ``inherits``/``i`` When present, value is a comma-separated list of classes from which this class is derived (i.e. inherits from). ``input``/``F`` The name of source file where ``name`` is defined or referenced. ``k`` `Kind `_ of tag as one-letter. Enabled by default. This field has no long-name. See also ``kind``/``z`` flag. ``K`` `Kind `_ of tag as long-name. This field has no long-name. See also ``kind``/``z`` flag. ``kind``/``z`` Include the ``kind:`` key in `kind field `_. See also ``k`` and ``K`` flags. ``language``/``l`` Language of source file containing tag ``line``/``n`` The line number where ``name`` is defined or referenced in ``input``. ``name``/``N`` The name of language objects. ``nth``/``o`` The order in the parent scope. (i.e. 4th parameter in the function). ``pattern``/``P`` Can be used to search the ``name`` in ``input`` ``roles``/``r`` Roles assigned to the tag. See "`Roles`_" for more details. ``s`` Scope of tag definition. Enabled by default. This field has no long-name. See also ``scope``/``Z`` flag. ``scope``/``Z`` Prepend the ``scope:`` key to scope (``s``) field. See also ``s`` flag. ``scopeKind``/``p`` Kind of scope as long-name ``signature``/``S`` When present, value is a language-dependent representation of the signature of a routine (e.g. prototype or parameter list). A routine signature in its complete form specifies the return type of a routine and its formal argument list. This extension field is presently supported only for C-based languages and does not include the return type. ``typeref``/``t`` Type and name of a variable, typedef, or return type of callable like function as ``typeref:`` field. Enabled by default. Kinds ...... ``kind`` is a field which represents the *kind* of language object specified by a tag. Kinds used and defined are very different between parsers. For example, C language defines ``macro``, ``function``, ``variable``, ``typedef``, etc. ``--kinds-(|all)=[+|-](|*)`` option specifies a list of language-specific kinds of tags (or kinds) to include in the output file for a particular language. See the output of "``ctags --list-kinds-full``" for the complete list of the kinds. Its value is either one of the corresponding one-letter flags or a long-name flag. It is permitted (and is, in fact, the default) for the key portion of this field to be omitted. The optional behaviors are controlled with the ``--fields`` option as follows. .. code-block:: console $ ctags -o - kinds.c foo kinds.c /^int foo() {$/;" f typeref:typename:int $ ctags --fields=+k -o - kinds.c foo kinds.c /^int foo() {$/;" f typeref:typename:int $ ctags --fields=+K -o - kinds.c foo kinds.c /^int foo() {$/;" function typeref:typename:int $ ctags --fields=+z -o - kinds.c foo kinds.c /^int foo() {$/;" kind:f typeref:typename:int $ ctags --fields=+zK -o - kinds.c foo kinds.c /^int foo() {$/;" kind:function typeref:typename:int Roles ...... *Role* is a newly introduced concept in Universal Ctags. Role is a concept associated with reference tags, and is not implemented widely yet. As described previously in "`Kinds`_", the ``kind`` field represents the type of language object specified with a tag, such as a function vs. a variable. Specific kinds are defined for reference tags, such as the C++ kind ``header`` for header file, or Java kind ``package`` for package statements. For such reference kinds, a ``roles`` field can be added to distinguish the role of the reference kind. In other words, the ``kind`` field identifies the *what* of the language object, whereas the ``roles`` field identifies the *how* of a referenced language object. Roles are only used with specific kinds. For a definition tag, this field takes ``def`` as a value. For example, ``Baz`` is tagged as a reference tag with kind ``package`` and with role ``imported`` with the following code. .. code-block:: java package Bar; import Baz; class Foo { // ... } .. code-block:: console $ ctags --fields=+KEr -uo - roles.java Bar roles.java /^package Bar;$/;" package roles:def Foo roles.java /^class Foo {$/;" class roles:def $ ctags --fields=+EKr --extras=+r -uo - roles.java Bar roles.java /^package Bar;$/;" package roles:def Baz roles.java /^import Baz;$/;" package roles:imported extras:reference Foo roles.java /^class Foo {$/;" class roles:def ``--roles-(|all).(|all)=[+|-][|*]`` option specifies a list of kind-specific roles of tags to include in the output file for a particular language. Inquire the output of "``ctags --list-roles``" for the list of roles. .. _extras: Extras ~~~~~~ Generally, ctags tags only language objects appearing in source files, as is. In other words, a value for a ``name:`` field should be found on the source file associated with the ``name:``. An ``extra`` type tag (*extra*) is for tagging a language object with a processed name, or for tagging something not associated with a language object. A typical extra tag is ``qualified``, which tags a language object with a class-qualified or scope-qualified name. ``--extras-(|all)=[+|-][|*]`` option specifies whether to include extra tag entries for certain kinds of information. Inquire the output of ``ctags --list-extras`` for the list of extras. The meaning of major extras is as follows (long-name flag/one-letter flag): ``anonymous``/none Include an entry for the language object that has no name like lambda function. This extra has no one-letter flag and is enabled by default. The extra tag is useful as a placeholder to fill scope fields for language objects defined in a language object with no name. .. code-block:: C struct { double x, y; } p = { .x = 0.0, .y = 0.0 }; '``x``' and '``y``' are the members of a structure. When filling the scope fields for them, ctags has trouble because the struct where '``x``' and '``y``' belong to has no name. For overcoming the trouble, ctags generates an anonymous extra tag for the struct and fills the scope fields with the name of the extra tag. .. code-block:: console $ ctags --fields=-f -uo - input.c __anon9f26d2460108 input.c /^struct {$/;" s x input.c /^ double x, y;$/;" m struct:__anon9f26d2460108 y input.c /^ double x, y;$/;" m struct:__anon9f26d2460108 p input.c /^} p = { .x = 0.0, .y = 0.0 };$/;" v typeref:struct:__anon9f26d2460108 The above tag output has ``__anon9f26d2460108`` as an anonymous extra tag. The typeref field of '``p``' also receives the benefit of it. ``fileScope``/``F`` Indicates whether tags scoped only for a single file (i.e. tags which cannot be seen outside of the file in which they are defined, such as language objects with ``static`` modifier of C language) should be included in the output. See also the ``-h`` option. This extra tag is enabled by default. Add ``--extras=-F`` option not to output tags scoped only for a single-file. This is the replacement for ``--file-scope`` option of Exuberant Ctags. .. code-block:: c static int f() { return 0; } int g() { return 0; } .. code-block:: console $ ctags -uo - filescope.c f filescope.c /^static int f() {$/;" f typeref:typename:int file: g filescope.c /^int g() {$/;" f typeref:typename:int $ ctags --extras=-F -uo - filescope.c g filescope.c /^int g() {$/;" f typeref:typename:int ``inputFile``/``f`` Include an entry for the base file name of every source file (e.g. ``example.c``), which addresses the first line of the file. This flag is the replacement for ``--file-tags`` hidden option of Exuberant Ctags. If the ``end:`` field is enabled, the end line number of the file can be attached to the tag. (However, ctags omits the ``end:`` field if no newline is in the file like an empty file.) By default, ctags doesn't create the ``inputFile``/``f`` extra tag for the source file when ctags doesn't find a parser for it. Enabling ``Unknown`` parser with ``--languages=+Unknown`` forces ctags to create the extra tags for any source files. The etags mode enables the ``Unknown`` parser implicitly. ``nulltag``/``z`` Include tags (*null tags*) having empty strings as their names. Generally speaking, trying to make a null tag is a sign of a parser bug or broken input. ctags warns such trying or throws the null tag away. To suppress the warnings, use ``--quiet`` option. On the other hand, null tags are valid in some languages. Consider ``{"": val}`` in a JavaScript source code. The empty string is valid as a key. If a parser intentionally makes a null tag (a valid null tag), ctags doesn't warn but discard it by default. The discards are due because some output formats may not consider null tags. With ``nulltag``/``z`` extra, you can force ctags to emit the nulltags. This extra is effective only if the output format supports null tags. ``--list-output-formats`` option tells you which output formats support null tags. (since version 6.2.0) ``pseudo``/``p`` Include pseudo-tags. Enabled by default unless the tag file is written to standard output. See :ref:`ctags-client-tools(7) ` about the detail of pseudo-tags. ``qualified``/``q`` Include an extra class-qualified or namespace-qualified tag entry for each tag which is a member of a class or a namespace. This may allow easier location of a specific tags when multiple occurrences of a tag name occur in the tag file. Note, however, that this could potentially more than double the size of the tag file. The actual form of the qualified tag depends upon the language from which the tag was derived (using a form that is most natural for how qualified calls are specified in the language). For C++ and Perl, it is in the form ``class::member``; for Eiffel and Java, it is in the form ``class.member``. Note: Using backslash characters as separators forming qualified name in PHP. However, in tags output of Universal Ctags, a backslash character in a name is escaped with a backslash character. See :ref:`tags(5) ` about the escaping. The following example demonstrates the ``qualified`` extra tag. .. code-block:: Java class point { double x; }; For the above source file, ctags tags ``point`` and ``x`` by default. If the ``qualified`` extra is enabled from the command line (``--extras=+q``), then ``point.x`` is also tagged even though the string "``point.x``" is not in the source code. .. code-block:: console $ ctags --fields=+K -uo - qualified.java point qualified.java /^class point {$/;" class x qualified.java /^ double x;$/;" field class:point $ ctags --fields=+K --extras=+q -uo - qualified.java point qualified.java /^class point {$/;" class x qualified.java /^ double x;$/;" field class:point point.x qualified.java /^ double x;$/;" field class:point ``reference``/``r`` Include reference tags. See "`TAG ENTRIES`_" about reference tags. The following example demonstrates the ``reference`` extra tag. .. code-block:: c #include #include "utils.h" #define X #undef X The ``roles:system`` or ``roles:local`` fields will be added depending on whether the include file name begins with '``<``' or not. "``#define X``" emits a definition tag. On the other hand "``#undef X``" emits a reference tag. .. code-block:: console $ ctags --fields=+EKr -uo - inc.c X inc.c /^#define X$/;" macro file: roles:def extras:fileScope $ ctags --fields=+EKr --extras=+r -uo - inc.c stdio.h inc.c /^#include /;" header roles:system extras:reference utils.h inc.c /^#include "utils.h"/;" header roles:local extras:reference X inc.c /^#define X$/;" macro file: roles:def extras:fileScope X inc.c /^#undef X$/;" macro file: roles:undef extras:fileScope,reference Language-specific fields and extras ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Exuberant Ctags has the concept of *fields* and *extras*. They are common between parsers of different languages. Universal Ctags extends this concept by providing language-specific fields and extras. .. Note: kinds are language-specific since e-ctags. roles are new to u-ctags. .. TODO: move the following "Hot to ..." sections to FAQ man page when available HOW TO USE WITH VI ------------------ ``vi(1)`` will, by default, expect a tag file by the name ``tags`` in the current directory. Once the tag file is built, the following commands exercise the tag indexing feature: ``vi -t tag`` Start vi and position the cursor at the file and line where ``tag`` is defined. ``:ta tag`` Find a tag. ``Ctrl-]`` Find the tag under the cursor. ``Ctrl-T`` Return to previous location before jump to tag (not widely implemented). HOW TO USE WITH GNU EMACS ------------------------- ``emacs(1)`` will, by default, expect a tag file by the name ``TAGS`` in the current directory. Once the tag file is built, the following commands exercise the tag indexing feature: ``M-x visit-tags-table FILE `` Select the tag file, ``FILE``, to use. ``M-. [TAG] `` Find the first definition of TAG. The default tag is the identifier under the cursor. ``M-*`` Pop back to where you previously invoked ``M-.``. ``C-u M-.`` Find the next definition for the last tag. For more commands, see the Tags topic in the Emacs info document. HOW TO USE WITH NEDIT --------------------- NEdit version 5.1 and later can handle the new extended tag file format (see ``--format``). * To make NEdit use the tag file, select "File->Load Tags File". * To jump to the definition for a tag, highlight the word, then press ``Ctrl-D``. NEdit 5.1 can read multiple tag files from different directories. Setting the X resource ``nedit.tagFile`` to the name of a tag file instructs NEdit to automatically load that tag file at startup time. CAVEATS ------- Because ctags is neither a preprocessor nor a compiler, use of preprocessor macros can fool ctags into either missing tags or improperly generating inappropriate tags. Although ctags has been designed to handle certain common cases, this is the single biggest cause of reported problems. In particular, the use of preprocessor constructs which alter the textual syntax of C can fool ctags. You can work around many such problems by using the ``-I`` option. Note that since ctags generates patterns for locating tags (see the ``--excmd`` option), it is entirely possible that the wrong line may be found by your editor if there exists another source line which is identical to the line containing the tag. The following example demonstrates this condition: .. code-block:: C int variable; /* ... */ void foo(variable) int variable; { /* ... */ } Depending upon which editor you use and where in the code you happen to be, it is possible that the search pattern may locate the local parameter declaration before it finds the actual global variable definition, since the lines (and therefore their search patterns) are identical. This can be avoided by use of the ``--excmd=n`` option. INCOMPATIBLE CHANGES -------------------- See :ref:`ctags-incompatibilities(7) ` about incompatibilities between Universal Ctags and Exuberant Ctags. This section describes major incompatibilities within versions of Universal Ctags. Unifying the kind Letter for ``unknown`` kinds Some parsers used different kind letters for ``unknown`` kinds. EmacsLisp used ``u``. Go used ``u``. Julian used ``x``. Lisp used ``u``. Lua used ``X``. and Python used ``x``. They were unified to ``Y`` in the during development of version 5.9.x. BUGS ---- ctags has more options than ``ls(1)``. ctags assumes the input file is written in the correct grammar. Otherwise output of ctags is undefined. In other words it has garbage in, garbage out (GIGO) feature. .. TODO: move the following paragraph to parser-cxx.rst. When parsing a C++ member function definition (e.g. ``className::function``), ctags cannot determine whether the scope specifier is a class name or a namespace specifier and always lists it as a class name in the scope portion of the extension fields. Also, if a C++ function is defined outside of the class declaration (the usual case), the access specification (i.e. public, protected, or private) and implementation information (e.g. virtual, pure virtual) contained in the function declaration are not known when the tag is generated for the function definition. It will, however be available for prototypes (e.g. ``--kinds-c++=+p``). No qualified tags are generated for language objects inherited into a class. ENVIRONMENT VARIABLES --------------------- ``TMPDIR`` On Unix-like hosts where ``mkstemp(3)`` is available, the value of this variable specifies the directory in which to place temporary files. This can be useful if the size of a temporary file becomes too large to fit on the partition holding the default temporary directory defined at compilation time. ctags creates temporary files only if either (1) an emacs-style tag file is being generated, (2) the tag file is being sent to standard output, or (3) the program was compiled to use an internal sort algorithm to sort the tag files instead of the ``sort(1)`` utility of the operating system. If the ``sort(1)`` utility of the operating system is being used, it will generally observe this variable also. Note that if ctags is setuid, the value of ``TMPDIR`` will be ignored. FILES ----- Output files ~~~~~~~~~~~~ ``tags`` The default tag file created by ctags. ``TAGS`` The default tag file created by etags. Preloading option files ~~~~~~~~~~~~~~~~~~~~~~~ ``$XDG_CONFIG_HOME/ctags/*.ctags``, or ``$HOME/.config/ctags/*.ctags`` if ``$XDG_CONFIG_HOME`` is not defined ``$HOME/.ctags.d/*.ctags`` ``$HOMEDRIVE$HOMEPATH/ctags.d/*.ctags`` (on MS Windows only) ``.ctags.d/*.ctags`` ``ctags.d/*.ctags`` If any of these configuration files exist, each will be expected to contain a set of default options which are read in the order listed when ctags starts, but before any command line options are read. This makes it possible to set up personal or project-level defaults. It is possible to compile ctags to read an additional configuration file before any of those shown above, which will be indicated if the output produced by the ``--version`` option lists the ``custom-conf`` feature. Options appearing on the command line will override options specified in these files. Only options will be read from these files. Note that the option files are read in line-oriented mode in which spaces are significant (since shell quoting is not possible) but spaces at the beginning of a line are ignored. Each line of the file is read as one command line parameter (as if it were quoted with single quotes). Therefore, use new lines to indicate separate command-line arguments. A line starting with '``#``' is treated as a comment. ``*.ctags`` files in a directory are loaded in alphabetical order. Default optlib path list ~~~~~~~~~~~~~~~~~~~~~~~~ ``$XDG_CONFIG_HOME/ctags``, or ``$HOME/.config/ctags`` if ``$XDG_CONFIG_HOME`` is not defined ``$HOME/.ctags.d`` ``$HOMEDRIVE$HOMEPATH/ctags.d`` (on MS Windows only) These directories are parts of the optlib path list by default. See "`Option File Options`_" about the optlib path list. If you have a set of options that you want to enable conditionally, make a directory in the path in the optlib path list, and put the options to the files having .ctags as extensions under the directory. ``--options=`` is for enabling the options. For example, consider you have some options you want to enable only when tagging the Linux kernel source tree. In that case, make ``$HOME/.ctags.d/linux`` directory, put the options to ``$HOME/.ctags.d/linux/my.ctags``. If you have many options, you can split them into multiple files like ``$HOME/.ctags.d/linux/device-driver.ctags`` and ``$HOME/.ctags.d/linux/network-stack.ctags``. Either way, you can enable the options in the .ctags file(s) under the directory by adding ``--options=linux`` to your ctags command line. SEE ALSO -------- See :ref:`ctags-optlib(7) ` for defining (or extending) a parser in a configuration file. See :ref:`tags(5) ` for the format of tag files. See :ref:`ctags-incompatibilities(7) ` about known incompatible changes with Exuberant Ctags. See :ref:`ctags-client-tools(7) ` if you are interested in writing a tool for processing tags files. See :ref:`ctags-lang-python(7) ` about python input specific notes. See :ref:`readtags(1) ` about a client tool for binary searching a name in a sorted tags file. The official Universal Ctags web site at: https://ctags.io/ Also ``ex(1)``, ``vi(1)``, ``elvis(1)``, or, better yet, ``vim(1)``, the official editor of ctags. For more information on ``vim(1)``, see the Vim web site at: https://www.vim.org/ About the file format for ``TAGS``, see `emacs git `_. AUTHOR ------ Universal Ctags project https://ctags.io/ Darren Hiebert http://DarrenHiebert.com/ MOTIVATION ---------- "Think ye at all times of rendering some service to every member of the human race." "All effort and exertion put forth by man from the fullness of his heart is worship, if it is prompted by the highest motives and the will to do service to humanity." -- From the Baha'i Writings CREDITS ------- This version of ctags (Universal Ctags) derived from the repository, known as fishman-ctags, started by Reza Jelveh. The fishman-ctags was derived from Exuberant Ctags. Some parsers are taken from ``tagmanager`` of the Geany (https://www.geany.org/) project. Exuberant Ctags was originally derived from and inspired by the ctags program by Steve Kirkendall that comes with the Elvis vi clone (though virtually none of the original code remains). Credit is also due Bram Moolenaar , the author of vim, who has devoted so much of his time and energy both to developing the editor as a service to others, and to helping the orphans of Uganda. The section entitled "`HOW TO USE WITH GNU EMACS`_" was shamelessly stolen from the info page for GNU etags. --- ## File: docs/man/ctags-faq.7.rst .. _ctags-faq(7): ============================================================== ctags-faq ============================================================== Universal Ctags FAQ :Version: 6.2.0 :Manual group: Universal Ctags :Manual section: 7 This is the Universal Ctags FAQ (Frequently-Asked Questions). It is based on `Exuberant Ctags FAQ `_ .. contents:: DESCRIPTION ----------- .. TODO: https://github.com/universal-ctags/ctags/issues/2312 #1421: feature: clean up stale tags when appending (`-a`) #2356: can't pre-process the macro but it works with Exuberant Ctags 5.8 #2540: C/C++：conditional compilation like #ifdef will cause parse error What is the difference between Universal Ctags and Exuberant Ctags? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Universal Ctags is an unofficial fork of Exuberant Ctags. The differences are summarized in :ref:`ctags-incompatibilities(7) ` man page. The most notable one is that Universal Ctags doesn't read ``~/.ctags`` file. Instead, it reads ``*.ctags`` under ``~/.ctags.d`` directory. How can I avoid having to specify my favorite option every time? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Either by setting the environment variable ``CTAGS`` to your custom options, or putting them into a ``~/.ctags.d/anyname.ctags`` file in your home directory. What are these strange bits of text beginning with ``;"`` which follow many of the lines in the tag file? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ These are *extension flags*. They are added in order to provide extra information about the tag that may be utilized by the editor in order to more intelligently handle tags. They are appended to the EX command part of the tag line in a manner that provides backwards compatibility with existing implementations of the Vi editor. The semicolon is an EX command separator and the double quote begins an EX comment. Thus, the extension flags appear as an EX comment and should be ignored by the editor when it processes the EX command. Some non-vi editors, however, implement only the bare minimum of EX commands in order to process the search command or line number in the third field of the tag file. If you encounter this problem, use the option ``--format=1`` to generate a tag file without these extensions (remember that you can set the CTAGS environment variable to any default arguments you wish to supply). Then ask the supplier of your editor to implement handling of this feature of EX commands. Why can't I jump to ``class::member``? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Because, by default, ctags only generates tags for the separate identifiers found in the source files. If you specify the ``--extra=+q`` option, then ctags will also generate a second, class-qualified tag for each class member (data and function/method) in the form ``class::member`` for C++, and in the form ``class.method`` for Eiffel and Java. Why do I end up on the wrong line when I jump to a tag? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ By default, ctags encodes the line number in the file where macro (``#define``) tags are found. This was done to remain compatible with the original UNIX version of ctags. If you change the file containing the tag without rebuilding the tag file, the location of tag in the tag file may no longer match the current location. In order to avoid this problem, you can specify the option ``--excmd=p``, which causes ctags to use a search pattern to locate macro tags. I have never uncovered the reason why the original UNIX ctags used line numbers exclusively for macro tags, but have so far resisted changing the default behavior of Exuberant (and Universal) Ctags to behave differently. How do I jump to the tag I want instead of the wrong one by the same name? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A tag file is simple a list of tag names and where to find them. If there are duplicate entries, you often end up going to the wrong one because the tag file is sorted and your editor locates the first one in the tag file. Standard Vi provides no facilities to alter this behavior. However, Vim has some nice features to minimize this problem, primarily by examining all matches and choosing the best one under the circumstances. Vim also provides commands which allow for selection of the desired matching tag. How can I locate all references to a specific function or variable? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ There are several packages already available which provide this capability. Namely, these are: GLOBAL source code tag system, GNU id-utils, cscope, and cflow. As of this writing, they can be found in the following locations: - GLOBAL: http://www.gnu.org/software/global - id-utils: http://www.gnu.org/software/idutils/idutils.html - cscope: http://cscope.sourceforge.net - cflow: ftp://www.ibiblio.org/pub/Linux/devel/lang/c Why does appending tags to a tag file tag so long? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Sometimes, in an attempt to build a global tag file for all source files in a large source tree of many directories, someone will make an attempt to run ctags in append (``-a``) mode on every directory in the hierarchy. Each time ctags is invoked, its default behavior is to sort the tag file once the tags for that execution have been added. As the cumulative tag file grows, the sort time increases arithmetically. The best way to avoid this problem (and the most efficient) is to make use of the ``--recurse`` (or ``-R``) option of ctags by executing the following command in the root of the directory hierarchy (thus running ctags only once): .. code-block:: sh ctags -R If you really insist on running ctags separately on each directory, you can avoid the sort pass each time by specifying the option ``--sort=no``. Once the tag file is completely built, use the sort command to manually sort the final tag file, or let the final invocation of ctags sort the file. How should I set up tag files for a multi-level directory hierarchy? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ There are a few ways of approaching this: 1. A local tag file in each directory containing only the tags for source files in that directory. 2. One single big, global tag file present in the root directory of your hierarchy, containing all tags present in all source files in the hierarchy. 3. A local tag file in each directory containing only the tags for source files in that directory, in addition to one single global tag file present in the root directory of your hierarchy, containing all non-static tags present in all source files in the hierarchy. 4. A local tag file in each directory of the hierarchy, each one containing all tags present in source files in that directory and all non-static tags in every directory below it (note that this implies also having one big tag file in the root directory of the hierarchy). Each of these approaches has its own set of advantages and disadvantages, depending upon your particular conditions. Which approach is deemed best depends upon the following factors: A. The ability of your editor to use multiple tag files. If your editor cannot make use of multiple tag files (original vi implementations could not), then one large tag file is the only way to go if you ever desire to jump to tags located in other directories. If you never need to jump to tags in another directory (i.e. the source in each directory is entirely self-contained), then a local tag file in each directory will fit your needs. B. The time is takes for your editor to look up a tag in the tag file. The significance of this factor depends upon the size of your source tree and on whether the source files are located on a local or remote file system. For source and tag files located on a local file system, looking up a tag is not as big a hit as one might first imagine, since vi implementations typically perform a binary search on a sorted tag file. This may or may not be true for the editor you use. For files located on a remote file system, reading a large file is an expensive operation. C. Whether or not you expect the source code to change and the time it takes to rebuild a tag file to account for changes to the source code. While Universal Ctags is particularly fast in scanning source code (around 1-2 MB/sec), a large project may still result in objectionable delays if one wishes to keep their tag file(s) up to date on a frequent basis, or if the files are located on a remote file system. D. The presence of duplicate tags in the source code and the ability to handle them. The impact of this factor is influenced by the following three issues: 1. How common are duplicate tags in your project? 2. Does your editor provide any facilities for dealing with duplicate tags? While standard vi does not, many modern vi implementations, such as Vim have good facilities for selecting the desired match from the list of duplicates. If your editor does not support duplicate tags, then it will typically send you to only one of them, whether or not that is the one you wanted (and not even notifying you that there are other potential matches). 3. What is the significance of duplicate tags? For example, if you have two tags of the same name from entirely isolated software components, jumping first to the match found in component B while working in component A may be entirely misleading, distracting or inconvenient (to keep having to choose which one if your editor provides you with a list of matches). However, if you have two tags of the same name for parallel builds (say two initialization routines for different hosts), you may always want to specify which one you want. Of the approaches listed above, I tend to favor Approach 3. My editor of choice is Vim, which provides a rich set of features for handling multiple tag files, which partly influences my choice. If you are working with source files on a remote file system, then I would recommend either Approach 3 or Approach 4, depending upon the hit when reading the global tag file. The advantages of Approach 3 are many (assuming that your editor has the ability to support both multiple tag files and duplicate tags). All lookups of tag located in the current directory are fast and the local tag file can be quickly and easily regenerated in one second or less (I have even mapped a keystroke to do this easily). A lookup of a (necessarily non-static) tag found in another directory fails a lookup in the local tag file, but is found in the global tag file, which satisfies all cross-directory lookups. The global tag file can be automatically regenerated periodically with a cron job (and perhaps the local tag files also). Now I give an example of how you would implement Approach 3. Means of implementing the other approaches can be performed in a similar manner. Here is a visual representation of an example directory hierarchy: :: project `-----misccomp | `... `-----sysint `-----client | `-----hdrs | `-----lib | `-----src | `-----test `-----common | `-----hdrs | `-----lib | `-----src | `-----test `-----server `-----hdrs `-----lib `-----src `-----test Here is a recommended solution (conceptually) to build the tag files: 1. Within each of the leaf nodes (i.e. ``hdrs``, ``lib``, ``src``, ``test``) build a tag file using "``ctags *.[ch]``". This can be easily be done for the whole hierarchy by making a shell script, call it ``dirtags``, containing the following lines: .. code-block:: sh #!/bin/sh cd $1 ctags * Now execute the following command: .. code-block:: sh find * -type d -exec dirtags {} \; These tag files are trivial (and extremely quick) to rebuild while making changes within a directory. The following Vim key mapping is quite useful to rebuild the tag file in the directory of the current source file: .. code-block:: text :nmap ,t :!(cd %:p:h;ctags *.[ch])& 2. Build the global tag file: .. code-block:: sh cd ~/project ctags --file-scope=no -R thus constructing a tag file containing only non-static tags for all source files in all descendent directories. 3. Configure your editor to read the local tag file first, then consult the global tag file when not found in the local tag file. In Vim, this is done as follows: .. code-block:: text :set tags=./tags,tags,~/project/tags If you wish to implement Approach 4, you would need to replace the ``dirtags`` script of step 1 with the following: .. code-block:: sh #!/bin/sh cd $1 ctags * # Now append the non-static tags from descendent directories find * -type d -prune -print | ctags -aR --file-scope=no -L- And replace the configuration of step 3 with this: .. code-block:: text :set tags=./tags;$HOME,tags As a caveat, it should be noted that step 2 builds a global tag file whose file names will be relative to the directory in which the global tag file is being built. This takes advantage of the Vim ``tagrelative`` option, which causes the path to be interpreted a relative to the location of the tag file instead of the current directory. For standard vi, which always interprets the paths as relative to the current directory, we need to build the global tag file with absolute path names. This can be accomplished by replacing step 2 with the following: .. code-block:: sh cd ~/project ctags --file-scope=no -R `pwd` Does Universal Ctags support Unicode file names? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. MEMO: from https://github.com/universal-ctags/ctags/issues/1837 Yes, Unicode file names are supported on unix-like platforms (Linux, macOS, Cygwin, etc.). However, on MS Windows, you need to use Windows 10 version 1903 or later to use Unicode file names. (This is an experimental feature, though.) On older versions on Windows, Universal Ctags only support file names represented in the current code page. If you still want to use Unicode file names on them, use Cygwin or MSYS2 version of Universal Ctags as a workaround. Why does zsh cause "zsh: no matches found" error? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. MEMO: from https://github.com/universal-ctags/ctags/issues/2842 zsh causes error on the following cases; .. code-block:: sh ctags --extra=+* ... ctags --exclude=foo/* ... This is the 2nd most significant incompatibility *feature* of zsh. Cited from "Z-Shell Frequently-Asked Questions", "`2.1: Differences from sh and ksh `_"; ... The next most classic difference is that unmatched glob patterns cause the command to abort; set ``NO_NOMATCH`` for those. You may add "``setopt nonomatch``" on your ``~/.zshrc``. Or you can escape glob patterns with backslash; .. code-block:: sh ctags --extra=+\* ... ctags --exclude=foo/\* ... Or quote them; .. code-block:: sh ctags '--extra=+*' ... ctags '--exclude=foo/*' ... SEE ALSO -------- The official Universal Ctags web site at: https://ctags.io/ :ref:`ctags(1) `, :ref:`tags(5) ` AUTHOR ------ This FAQ is based on `Exuberant Ctags FAQ `_ by Darren Hiebert and vberthoux@users.sourceforge.net Universal Ctags project: https://ctags.io/ --- ## File: docs/man/ctags-incompatibilities.7.rst .. _ctags-incompatibilities(7): ============================================================== ctags-incompatibilities ============================================================== Incompatibilities between Universal Ctags and Exuberant Ctags :Version: 6.2.0 :Manual group: Universal Ctags :Manual section: 7 SYNOPSIS -------- | **ctags** [options] [file(s)] | **etags** [options] [file(s)] DESCRIPTION ----------- This page describes major incompatible changes introduced to Universal Ctags forked from Exuberant Ctags. Option files loading at starting up time (preload files) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Universal Ctags doesn't load ``~/.ctags`` at starting up time. File paths for preload files are changed. See "FILES" section of :ref:`ctags(1) `. Environment variables for arranging command lines ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Universal Ctags doesn't read ``CTAGS`` and/or ``ETAGS`` environment variables. Behavior when ``--excmd=mixed`` is given ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Exuberant Ctags uses line numbers as addresses for C preprocessor macro definition tags. Universal Ctags uses patterns for the tags. Incompatibilities in command line interface ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Ordering in a command line .................................................................................... .. NOTE: #1889 The command line format of Universal Ctags is "``ctags [options] [source_file(s)]``" following the standard POSIX convention. Exuberant Ctags accepts a option following a source file. .. code-block:: console $ ctags -o - foo.c --list-kinds=Sh f functions Universal Ctags warns and ignores the option ``--list-kinds=Sh`` as follows. .. code-block:: console $ ctags -o - foo.c --list-kinds=Sh ctags: Warning: cannot open input file "--list-kinds=Sh" : No such file or directory a foo.c /^void a () {}$/;" f typeref:typename:void b foo.c /^void b () {}$/;" f typeref:typename:void The order of application of patterns and extensions in ``--langmap`` .................................................................................... When applying mappings for a name of given source file, Exuberant Ctags tests file name patterns *AFTER* file extensions (*e-map-order*). Universal Ctags does this differently; it tests file name patterns *BEFORE* file extensions (*u-map-order*). This incompatible change is introduced to deal with the following situation: * ``build.xml`` as a source file, * The Ant parser declares it handles a file name pattern ``build.xml``, and * The XML parser declares it handles a file extension ``.xml``. Which parser should be used for parsing ``build.xml``? The assumption of Universal Ctags is the user may want to use the Ant parser; the file name pattern it declares is more specific than the file extension that the XML parser declares. However, e-map-order chooses the XML parser. So Universal Ctags uses the u-map-order even though it introduces an incompatibility. ``--list-map-extensions=`` and ``--list-map-patterns=`` options are helpful to verify and the file extensions and the file name patterns of given **. Remove ``--file-tags`` and ``--file-scope`` options .................................................................................... Even in Exuberant Ctags, ``--file-tags`` is not documented in its man page. Instead of specifying ``--file-tags`` or ``--file-tags=yes``, use ``--extras=+f`` or ``--extras=+{inputFile}``. Instead of specifying ``--file-tags=no``, use ``--extras=-f`` or ``--extras=-{inputFile}``. Universal Ctags introduces ``F/fileScope`` extra as the replacement for ``--file-scope`` option. Instead of specifying ``--file-tags`` or ``--file-tags=yes``, use ``--extras=+F`` or ``--extras=+{fileScope}``. Instead of specifying ``--file-tags=no``, use ``--extras=-F`` or ``--extras=-{fileScope}``. Incompatibilities in language and kind definitions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Language name defined with ``--langdef=name`` option .................................................................................... The characters you can use are more restricted than Exuberant Ctags. For more details, see the description of ``--langdef=name`` in :ref:`ctags-optlib(7) `. Obsoleting ``---kinds`` option .................................................................................... Some options have ** as parameterized parts in their name like ``--foo-=...`` or ``---foo=...``. The most of all such options in Exuberant Ctags have the former form, ``--foo-=...``. The exception is ``---kinds``. Universal Ctags uses the former form for all ** parameterized option. Use ``--kinds-`` instead of ``---kinds`` in Universal Ctags. ``---kinds`` still works but it will be removed in the future. The former form may be friendly to shell completion engines. Disallowing to define a kind with ``file`` as name .................................................................................... The kind name ``file`` is reserved. Using it as part of kind spec in ``--regex-`` option is now disallowed. Disallowing to define a kind with '``F``' as letter .................................................................................... The kind letter '``F``' is reserved. Using it as part of a kind spec in ``--regex-`` option is now disallowed. Disallowing to use other than alphabetical character as kind letter .................................................................................... Exuberant Ctags accepts a character other than alphabetical character as kind letter in ``--regex-=...`` option. Universal Ctags accepts only an alphabetical character. Acceptable characters as parts of a kind name .................................................................................... Exuberant Ctags accepts any character as a part of a kind name defined with ``--regex-=/regex/replacement/kind-spec/``. Universal Ctags accepts only an alphabetical character as the initial letter of a kind name. Universal Ctags accepts only an alphabetical character or numerical character as the rest letters. An example:: --regex-Foo=/abstract +class +([a-z]+)/\1/a,abstract class/i Universal Ctags rejects this because the kind name, ``abstract class``, includes a whitespace character. This requirement is for making the output of Universal Ctags follow the tags file format. A combination of a kind letter and a kind name .................................................................................... In Universal Ctags, the combination of a kind letter and a kind name must be unique in a language. You cannot define more than one kind reusing a kind letter with different kind names. You cannot define more than one kind reusing a kind name with different kind letters. An example:: --regex-Foo=/abstract +class +([a-z]+)/\1/a,abstractClass/i --regex-Foo=/attribute +([a-z]+)/\1/a,attribute/i Universal Ctags rejects this because the kind letter, '``a``', used twice for defining a kind ``abstractClass`` and ``attribute``. Incompatibilities in tags file format ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Using numerical character in the name part of tag tagfield .................................................................................... The version 2 tags file format, the default output format of Exuberant Ctags, accepts only alphabetical characters in the name part of tag tagfield. Universal Ctags introduces an exception to this specification; it may use numerical characters in addition to alphabetical characters as the letters other than initial letter of the name part. The kinds ``heading1``, ``heading2``, and ``heading3`` in the HTML parser are the examples. Truncating the pattern for long input lines .................................................................................... To prevent generating overly large tags files, a pattern field is truncated, by default, when its size exceeds 96 bytes. A different limit can be specified with ``--pattern-length-limit=N``. Specifying 0 as *N* results no truncation as Exuberant Ctags does not. Kind letters and names .................................................................................... A kind letter '``F``' and a kind name ``file`` are reserved in the main part. A parser cannot have a kind conflicting with these reserved ones. Some incompatible changes are introduced to follow the above rule. * Cobol's ``file`` kind is renamed to ``fileDesc`` because the kind name ``file`` is reserved. * Ruby's '``F``' (singletonMethod) is changed to '``S``'. * SQL's '``F``' (field) is changed to '``E``'. SEE ALSO -------- :ref:`ctags(1) `, :ref:`ctags-optlib(7) `, and :ref:`tags(5) `. --- ## File: docs/man/ctags-json-output.5.rst .. _ctags-json-output(5): ============================================================== ctags-json-output ============================================================== JSON based ctags output :Version: 1.0 :Manual group: Universal Ctags :Manual section: 5 SYNOPSIS -------- | **ctags** --output-format=json ... DESCRIPTION ----------- Universal Ctags supports `JSON `_ (strictly speaking `JSON Lines `_) output format if the ctags executable is built with ``libjansson``. JSON output goes to standard output by default. FORMAT ------ Each JSON line represents a tag. .. code-block:: console $ ctags --extras=+p --output-format=json --fields=-s input.py {"_type": "ptag", "name": "JSON_OUTPUT_VERSION", "path": "1.0", "pattern": "in development"} {"_type": "ptag", "name": "TAG_FILE_SORTED", "path": "1", "pattern": "0=unsorted, 1=sorted, 2=foldcase"} ... {"_type": "tag", "name": "Klass", "path": "/tmp/input.py", "pattern": "/^class Klass:$/", "language": "Python", "kind": "class"} {"_type": "tag", "name": "method", "path": "/tmp/input.py", "pattern": "/^ def method(self):$/", "language": "Python", "kind": "member", "scope": "Klass", "scopeKind": "class"} ... A key not starting with ``_`` is mapped to a field of ctags. "``--output-format=json --list-fields``" options list the fields. A key starting with ``_`` represents meta information of the JSON line. Currently only ``_type`` key is used. If the value for the key is ``tag``, the JSON line represents a regular tag. If the value is ``ptag``, the line represents a pseudo-tag. The output format can be changed in the future. ``JSON_OUTPUT_VERSION`` pseudo-tag provides a change client-tools to handle the changes. Current version is "1.0". A client-tool can extract the version with ``path`` key from the pseudo-tag. The JSON output format is newly designed and has no limitation found in the default tags file format. * The values for ``kind`` key are represented in long-name flags. No one-letter is here. * Scope names and scope kinds have distinguished keys: ``scope`` and ``scopeKind``. They are combined in the default tags file format. DATA TYPE USED IN A FIELD ------------------------- Values for the most of all keys are represented in JSON string type. However, some of them are represented in string, integer, and/or boolean type. "``--output-format=json --list-fields``" options show What kind of data type used in a field of JSON. .. code-block:: console $ ctags --output-format=json --list-fields #LETTER NAME ENABLED LANGUAGE JSTYPE FIXED DESCRIPTION F input yes NONE s-- no input file ... P pattern yes NONE s-b no pattern ... f file yes NONE --b no File-restricted scoping ... e end no NONE -i- no end lines of various items ... ``JSTYPE`` column shows the data types. '``s``' string '``i``' integer '``b``' boolean (true or false) For an example, the value for ``pattern`` field of ctags takes a string or a boolean value. VERSIONS -------- Change since "0.0" ~~~~~~~~~~~~~~~~~~ * New key ``kindName`` for ``TAG_ROLE_DESCRIPTION`` pseudo tag ``kindName`` is added to store the name of the kind in ``TAG_ROLE_DESCRIPTION`` pseudo tags. In 0.0, a "TAG_ROLE_DESCRIPTION" pseudo tag was printed like: .. code-block:: JSON {"_type": "ptag", "name": "TAG_ROLE_DESCRIPTION", "parserName": "LANG!KIND", } In 1.0, it is printed like: .. code-block:: JSON {"_type": "ptag", "name": "TAG_ROLE_DESCRIPTION", "parserName": "LANG", "kindName": "KIND", } SEE ALSO -------- :ref:`ctags(1) `, :ref:`tags(5) `, :ref:`ctags-client-tools(7) ` --- ## File: docs/man/ctags-lang-asm.7.rst .. _ctags-lang-asm(7): ============================================================== ctags-lang-asm ============================================================== Random notes about tagging Assembly language source code with Universal Ctags :Version: 6.2.0 :Manual group: Universal Ctags :Manual section: 7 SYNOPSIS -------- | **ctags** ... --languages=+Asm ... | **ctags** ... --language-force=Asm ... | **ctags** ... --map-Asm=+.asm ... | **ctags** ... --map-Asm=+.ASM ... | **ctags** ... --map-Asm=+.s ... | **ctags** ... --map-Asm=+.S ... DESCRIPTION ----------- This man page gathers random notes about tagging assembly language source code. The parser of Universal Ctags has been extended to support the source code to be processed with *GNU assembler* (*Gas*). PARAMETERS ---------- The Asm parser has some parameters for adapting it to different assembler implementations. Writing a parser for assembly language source code is not easy because the syntax for the language differ depending on the implementations of assemblers and target CPU architectures. For example, in *NASM*, `;` is a starter of a line comment. On the other hand, in Gas for i386, `;` is a line separator. The parameters explained this man page are for mitigating the gaps of syntax. Use ``--param-Asm.{parameter}={value}`` option for adjusting the value for a parameter. For example: .. code-block:: console $ ctags ... --param-Asm.runCPreProcessor=false ... This command line sets ``false`` to ``runCPreProcessor`` parameter. ``--list-params=Asm`` lists available parameters available in the Asm parser. ``runCPreProcessor``: running C preprocessor ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ By default, the CPreProcessor parser processes the assembly language source code before the Asm parser does. The main effects of running the CPreProcessor parser; * lines started from `//` are stripped as comments, * areas surrounded by the pair of `/*` and `*/` are stripped as comments, and * macros defined with `#define` are extracted as tags. Set ``runCPreProcessor`` to ``false`` for disabling the CPreProcessor parser running before the Asm parser. ``commentCharsAtBOL``: adjusting line comment starter at the beginning of line ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ By default, the Asm parser ignores lines starting from `;`, `*`, or `@` as comments. `//` is also ignored if `runCPreProcessor` is `true`. ``commentCharsAtBOL`` is for changing the characters for line comments. `BOL` is acronym standing for "the beginning of line." The characters act as comment starters only if they are at the beginning of lines. The next example if for assembler input using `!` and `>` as the comment starter: .. code-block:: console $ ctags ... --param-Asm.commentCharsAtBOL='!>' ... ``commentCharsInMOL``: adjusting line comment starter in the middle of line ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Some dialects of assemblers support comments starting from the middle of line. A `;` character starts a comment anywhere on the line in Gas for CRIS for example. ``commentCharsInMOL`` is for specifying the character for line comments. `MOL` is acronym standing for "the middle of line." Unlike characters specified with ``commentCharsAtBOL``, the characters specified with ``commentCharsInMOL`` act as comment starts even if they are in the middle of lines. By default, the Asm parser has no ``commentCharsInMOL`` characters. ``extraLinesepChars``: adding line separators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The Asm parser processes its input line-oriented way. By default, the parser recognizes `\n` as a line separator. ``extraLinesepChars`` is for adding more line separators. In Gas for AArch64, the `;` character can be used as line separators. The next example for adjusting the Asm parser to the extra line separator: .. code-block:: console $ ctags ... --param-Asm.extraLinesepChars=';' ... EXPANDING C PREPROCESSOR MACROS ------------------------------- The Asm parser has the ability to expand **C preprocessor macros** before parsing. .. note:: Don't confuse C preprocessor macros and assembler implementation specific macros. The Asm parser expands only C preprocessor macros. Specifying following options are must for expansion:: --param-Asm.runCPreProcessor=true --fields=+{signature} --fields-CPreProcessor=+{macrodef} With the above options, the parser expands macros defined in command line with ``-D`` option. See :ref:`ctags(1) ` about the way to define a macro with the ``-D`` option. With ``--param-CPreProcessor._expand=1`` option, the parser expands macros defined in the current input file in addition to macros defined with the ``-D`` option. Though the parser expands macros, the parser doesn't extract language objects like labels as you expect. You must adjust the parser specific parameters to utilize the macro expansion feature effectively. See An example of macro expansion ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "input.S" .. code-block:: #define ENTRY(LABEL) .global LABEL ;\ LABEL ENTRY(main): nop "output.tags" with "--options=NONE -o - --param-Asm.useCPreProcessor=1 --param-CPreProcessor._expand=1 --fields=+{signature} --fields-CPreProcessor=+{macrodef} --param-Asm.extraLinesepChars=; --fields-CPreProcessor=+{macrodef} input.S" .. code-block:: tags ENTRY input.S /^#define ENTRY(/;" d file: signature:(LABEL) macrodef:.global LABEL ;LABEL main input.S /^ENTRY(main):$/;" l main input.S /^ENTRY(main):$/;" s The definition of `ENTRY` assumes `;` is a line separator in the host assembly language. ``--param-Asm.extraLinesepChars=;`` is for satisfying the assumption in ctags side. Known limitations ~~~~~~~~~~~~~~~~~ The parser has no ability to expand the macros defined outside of the current input file. The parser doesn't consider `#undef` when expanding. VERSIONS -------- Change since "0.0" ~~~~~~~~~~~~~~~~~~ * The kind ``section`` is deleted. The section specified with `.section` directive as tagged as ``placement`` role of ``section`` kind of ``Asm`` language. These kind and role are deleted. Instead, it is tagged as ``destination`` role of ``inputSection`` kind of ``LdScript`` language. SEE ALSO -------- :ref:`ctags(1) `, :ref:`ctags-lang-asm(7) `, Info entries for GNU assembler --- ## File: docs/man/ctags-lang-autoit.7.rst .. _ctags-lang-autoit(7): ============================================================== ctags-lang-autoit ============================================================== Random notes about tagging AutoIt source code with Universal Ctags :Version: 6.2.0 :Manual group: Universal Ctags :Manual section: 7 SYNOPSIS -------- | **ctags** ... --languages=+AutoIt ... | **ctags** ... --language-force=AutoIt ... | **ctags** ... --map-AutoIt=+.au3 ... DESCRIPTION ----------- This man page gathers random notes about tagging AutoIt source code. VERSIONS -------- Change since "0.0" ~~~~~~~~~~~~~~~~~~ * Drop ``$`` from tags for variables names. SEE ALSO -------- :ref:`ctags(1) ` --- ## File: docs/man/ctags-lang-automake.7.rst .. _ctags-lang-automake(7): ============================================================== ctags-lang-automake ============================================================== Random notes about tagging Automake source code (Makefile.am) with Universal Ctags :Version: 6.2.0 :Manual group: Universal Ctags :Manual section: 7 SYNOPSIS -------- | **ctags** ... --languages=+Automake ... | **ctags** ... --language-force=Automake ... | **ctags** ... --map-Automake=+.am ... DESCRIPTION ----------- This man page gathers random notes about tagging Automake source code (Makefile.am). VERSIONS -------- Change since "0.0" ~~~~~~~~~~~~~~~~~~ * Add ``canonicalizedName`` extra. * Add ``pseudodir`` kind. SEE ALSO -------- :ref:`ctags(1) ` --- ## File: docs/man/ctags-lang-c++.7.rst .. _ctags-lang-c++(7): ============================================================== ctags-lang-c++ ============================================================== Random notes about tagging C++ source code with Universal Ctags :Version: 6.2.0 :Manual group: Universal Ctags :Manual section: 7 SYNOPSIS -------- | **ctags** ... --languages=+C++ ... | **ctags** ... --language-force=C++ ... | **ctags** ... --map-C++=+.c++ ... | **ctags** ... --map-C++=+.cc ... | **ctags** ... --map-C++=+.cpp ... | **ctags** ... --map-C++=+.h ... | ... DESCRIPTION ----------- This man page gathers random notes about tagging C++ source code. VERSIONS -------- Change since "0.0" ~~~~~~~~~~~~~~~~~~ * New field ``section`` * New field ``alias`` Change since "1.1" ~~~~~~~~~~~~~~~~~~ * New kinds ``module`` and ``partition`` * New roles ``imported`` and ``exported`` for ``header`` kind SEE ALSO -------- :ref:`ctags(1) `, :ref:`ctags-lang-ldscript(7) `, `The new C/C++ parser `_ (https://docs.ctags.io/en/latest/parser-cxx.html)