ctags
(1g)
Name
ctags - generate tag file for Emacs, vi
Synopsis
etags [-aCDGIRVh] [-i file] [-l language]
[-o tagfile] [-r regexp] [--parse-stdin=file]
[--append] [--no-defines] [--globals] [--no-globals]
[--include=file] [--ignore-indentation]
[--language=language] [--members] [--no-members]
[--output=tagfile] [--regex=regexp] [--no-regex] [--help]
[--version] file ...
ctags [-aCdgIRVh] [-BtTuvwx] [-l language]
[-o tagfile] [-r regexp] [--parse-stdin=file]
[--append] [--backward-search] [--cxref] [--no-defines]
[--globals] [--no-globals] [--ignore-indentation]
[--language=language] [--members] [--no-members]
[--output=tagfile] [--regex=regexp] [--update] [--help]
[--version] file ...
Description
GNU Tools etags(1)
NAME
etags, ctags - generate tag file for Emacs, vi
SYNOPSIS
etags [-aCDGIRVh] [-i file] [-l language]
[-o tagfile] [-r regexp] [--parse-stdin=file]
[--append] [--no-defines] [--globals] [--no-globals]
[--include=file] [--ignore-indentation]
[--language=language] [--members] [--no-members]
[--output=tagfile] [--regex=regexp] [--no-regex] [--help]
[--version] file ...
ctags [-aCdgIRVh] [-BtTuvwx] [-l language]
[-o tagfile] [-r regexp] [--parse-stdin=file]
[--append] [--backward-search] [--cxref] [--no-defines]
[--globals] [--no-globals] [--ignore-indentation]
[--language=language] [--members] [--no-members]
[--output=tagfile] [--regex=regexp] [--update] [--help]
[--version] file ...
DESCRIPTION
The etags program is used to create a tag table file, in a
format understood by emacs(1); the ctags program is used to
create a similar table in a format understood by vi(1).
Both forms of the program understand the syntax of C, Objec-
tive C, C++, Java, Fortran, Ada, Cobol, Erlang, Forth, HTML,
LaTeX, Emacs Lisp/Common Lisp, Lua, Makefile, Pascal, Perl,
PHP, PostScript, Python, Prolog, Scheme and most assem-
bler-like syntaxes. Both forms read the files specified on
the command line, and write a tag table (defaults: TAGS for
etags, tags for ctags) in the current working directory.
Files specified with relative file names will be recorded in
the tag table with file names relative to the directory
where the tag table resides. If the tag table is in /dev or
is the standard output, however, the file names are made
relative to the working directory. Files specified with ab-
solute file names will be recorded with absolute file names.
Files generated from a source file--like a C file generated
from a source Cweb file--will be recorded with the name of
the source file. Compressed files are supported using gzip,
bzip2, and xz. The programs recognize the language used in
an input file based on its file name and contents. The
--language switch can be used to force parsing of the file
names following the switch according to the given language,
overriding guesses based on filename extensions.
OPTIONS
Some options make sense only for the vi style tag files pro-
duced by ctags; etags does not recognize them. The programs
accept unambiguous abbreviations for long option names.
-a, --append
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Append to existing tag file. (For vi-format tag files,
see also --update.)
-B, --backward-search
Tag files written in the format expected by vi contain
regular expression search instructions; the -B option
writes them using the delimiter `?', to search back-
wards through files. The default is to use the delim-
iter `/', to search forwards through files. Only ctags
accepts this option.
--declarations
In C and derived languages, create tags for function
declarations, and create tags for extern variables un-
less --no-globals is used.
-D, --no-defines
Do not create tag entries for C preprocessor constant
definitions and enum constants. This may make the tags
file much smaller if many header files are tagged.
--globals
Create tag entries for global variables in Perl and
Makefile. This is the default in C and derived lan-
guages.
--no-globals
Do not tag global variables in C and derived languages.
Typically this reduces the file size by one fourth.
-i file, --include=file
Include a note in the tag file indicating that, when
searching for a tag, one should also consult the tags
file file after checking the current file. Only etags
accepts this option.
-I, --ignore-indentation
Don't rely on indentation as much as we normally do.
Currently, this means not to assume that a closing
brace in the first column is the final brace of a func-
tion or structure definition in C and C++.
-l language, --language=language
Parse the following files according to the given lan-
guage. More than one such options may be intermixed
with filenames. Use --help to get a list of the avail-
able languages and their default filename extensions.
The `auto' language can be used to restore automatic
detection of language based on the file name. The
`none' language may be used to disable language parsing
altogether; only regexp matching is done in this case
(see the --regex option).
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--members
Create tag entries for variables that are members of
structure-like constructs in PHP. This is the default
for C and derived languages.
--no-members
Do not tag member variables.
--packages-only
Only tag packages in Ada files.
--parse-stdin=file
May be used (only once) in place of a file name on the
command line. etags will read from standard input and
mark the produced tags as belonging to the file FILE.
-o tagfile, --output=tagfile
Explicit name of file for tag table; for etags only, a
file name of - means standard output; overrides default
TAGS or tags. (But ignored with -v or -x.)
-r regexp, --regex=regexp
Make tags based on regexp matching for the files fol-
lowing this option, in addition to the tags made with
the standard parsing based on language. May be freely
intermixed with filenames and the -R option. The reg-
exps are cumulative, i.e., each such option will add to
the previous ones. The regexps are of one of the
forms:
[{language}]/tagregexp/[nameregexp/]modifiers
@regexfile
where tagregexp is used to match the tag. It should
not match useless characters. If the match is such
that more characters than needed are unavoidably
matched by tagregexp, it may be useful to add a
nameregexp, to narrow down the tag scope. ctags ig-
nores regexps without a nameregexp. The syntax of reg-
exps is the same as in emacs. The following character
escape sequences are supported: \a, \b, \d, \e, \f, \n,
\r, \t, \v, which respectively stand for the ASCII
characters BEL, BS, DEL, ESC, FF, NL, CR, TAB, VT.
The modifiers are a sequence of 0 or more characters
among i, which means to ignore case when matching; m,
which means that the tagregexp will be matched against
the whole file contents at once, rather than line by
line, and the matching sequence can match multiple
lines; and s, which implies m and means that the dot
character in tagregexp matches the newline char as
well.
The separator, which is / in the examples, can be any
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character different from space, tab, braces and @. If
the separator character is needed inside the regular
expression, it must be quoted by preceding it with \.
The optional {language} prefix means that the tag
should be created only for files of language language,
and ignored otherwise. This is particularly useful
when storing many predefined regexps in a file.
In its second form, regexfile is the name of a file
that contains a number of arguments to the --regex= op-
tion, one per line. Lines beginning with a space or
tab are assumed to be comments, and ignored.
Here are some examples. All the regexps are quoted to
protect them from shell interpretation.
Tag the DEFVAR macros in the emacs source files:
--regex='/[ \t]*DEFVAR_[A-Z_ \t(]+"\([^"]+\)"/'
Tag VHDL files (this example is a single long line,
broken here for formatting reasons):
--language=none --regex='/[ \t]*\(ARCHITECTURE\|\ CON-
FIGURATION\) +[^ ]* +OF/' --regex='/[ \t]*\ \(AT-
TRIBUTE\|ENTITY\|FUNCTION\|PACKAGE\( BODY\)?\ \|PROCE-
DURE\|PROCESS\|TYPE\)[ \t]+\([^ \t(]+\)/\3/'
Tag TCL files (this last example shows the usage of a
tagregexp):
--lang=none --regex='/proc[ \t]+\([^ \t]+\)/\1/'
A regexp can be preceded by {lang}, thus restricting it
to match lines of files of the specified language. Use
etags --help to obtain a list of the recognized lan-
guages. This feature is particularly useful inside
regex files. A regex file contains one regex per line.
Empty lines, and those lines beginning with space or
tab are ignored. Lines beginning with @ are references
to regex files whose name follows the @ sign. Other
lines are considered regular expressions like those
following --regex.
For example, the command
etags --regex=@regex.file *.c
reads the regexes contained in the file regex.file.
-R, --no-regex
Don't do any more regexp matching on the following
files. May be freely intermixed with filenames and the
--regex option.
-u, --update
Update tag entries for files specified on command line,
leaving tag entries for other files in place. Current-
ly, this is implemented by deleting the existing en-
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tries for the given files and then rewriting the new
entries at the end of the tags file. It is often
faster to simply rebuild the entire tag file than to
use this. Only ctags accepts this option.
-v, --vgrind
Instead of generating a tag file, write index (in
vgrind format) to standard output. Only ctags accepts
this option.
-x, --cxref
Instead of generating a tag file, write a cross refer-
ence (in cxref format) to standard output. Only ctags
accepts this option.
-h, -H, --help
Print usage information. Followed by one or more
--language=LANG prints detailed information about how
tags are created for LANG.
-V, --version
Print the current version of the program (same as the
version of the emacs etags is shipped with).
ATTRIBUTES
See attributes(5) for descriptions of the following at-
tributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | editor/gnu-emacs |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
SEE ALSO
`emacs' entry in info; GNU Emacs Manual, Richard Stallman.
cxref(1), emacs(1), vgrind(1), vi(1).
COPYING
Copyright (C) 1992, 1999, 2001-2013 Free Software Founda-
tion, Inc.
Permission is granted to make and distribute verbatim copies
of this document provided the copyright notice and this per-
mission notice are preserved on all copies.
Permission is granted to copy and distribute modified ver-
sions of this document under the conditions for verbatim
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GNU Tools etags(1)
copying, provided that the entire resulting derived work is
distributed under the terms of a permission notice identical
to this one.
Permission is granted to copy and distribute translations of
this document into another language, under the above condi-
tions for modified versions, except that this permission no-
tice may be stated in a translation approved by the Free
Software Foundation.
NOTES
This software was built from source available at https://ja-
va.net/projects/solaris-userland. The original community
source was downloaded from
http://ftp.gnu.org/gnu/emacs/emacs-24.3.tar.gz
Further information about this software can be found on the
open source community website at http://www.gnu.org/soft-
ware/emacs/.
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