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, Objective 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
assembler-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 absolute 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 produced by
ctags;
etags does not recognize them. The programs accept unambiguous
abbreviations for long option names.
- -a, --append
- 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 backwards through files. The
default is to use the delimiter ` /', 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 unless --no-globals is used. In Lisp,
create tags for (defvar foo) declarations.
- -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 languages.
- --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 function or structure definition in C and C++.
- -l language, --language=language
- Parse the following files according to the given language. More than one
such options may be intermixed with filenames. Use --help to get a
list of the available 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).
- --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 following 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 regexps
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 ignores
regexps without a nameregexp. The syntax of regexps 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 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= option, 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]*\(ARCHITECTURE\|\
CONFIGURATION\) +[^ ]* +OF/' --regex='/[ \t]*\
\(ATTRIBUTE\|ENTITY\|FUNCTION\|PACKAGE\( BODY\)?\
\|PROCEDURE\|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 languages. 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. Currently, this is implemented by
deleting the existing entries 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 reference (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).
SEE ALSO¶
`
emacs' entry in
info;
GNU Emacs Manual, Richard Stallman.
cxref(
1),
emacs(
1),
vgrind(
1),
vi(
1).
COPYING¶
Copyright (C) 1992, 1999, 2001-2015 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of this document
provided the copyright notice and this permission notice are preserved on all
copies.
Permission is granted to copy and distribute modified versions of this document
under the conditions for verbatim 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 conditions for modified versions, except
that this permission notice may be stated in a translation approved by the
Free Software Foundation.