etags(1)
NAME
etags, gctags - generate tag file for Emacs, vi
SYNOPSIS
etags [-aCDRSVh] [-i file] [-l language] [-i regexp] [-o
tagfile]
[--c++] [--no-defines] [--ignore-indentation]
[--language=language] [--regex=regexp] [--no-regexp]
[--help] [--version] [--include=file] [--output=tagfile]
[--append] file ...
gctags [-aCdRSVh] [-BtTuvwx] [-l language]
[-i regexp] [-o tagfile] [--c++] [--defines]
[--ignore-indentation] [--no-warn] [--cxref]
[--backward-search] [--forward-search] [--typedefs]
[--typedefs-and-c++] [--language=language]
[--regex=regexp] [--help] [--version]
[--output=tagfile] [--append] [--update] file ...
DESCRIPTION
The `etags' program is used to create a tag table file, in
a format understood by emacs(1); the `gctags' 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, C++, Fortran, Pascal, LaTeX, Scheme, Emacs Lisp/Common
Lisp, Erlang, Prolog 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 gctags) in the current working directory. Files spec-
ified with relative file names will be recorded in the tag
table with file names relative to the directory where the
tag table resides. Files specified with absolute file
names will be recorded with absolute file names. The pro-
grams 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 gctags; 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 con-
tain 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 gctags accepts this option.
-C, --c++
Treat files with `.c' and `.h' extensions as C++
code, not C code. Files with `.C', `.H', `.cxx',
`.hxx', or `.cc' extensions are always assumed to
be C++ code.
-d, --defines
Create tag entries for C preprocessor definitions,
too. This is the default behavior for etags, so
this option is only accepted by gctags.
-D, --no-defines
Do not create tag entries for C preprocessor defi-
nitions. This may make the tags file much smaller
if many header files are tagged. This is the de-
fault behavior for gctags, so this option is only
accepted by etags.
-l language, --language=language
Parse the following files according to the given
language. More than one such options may be inter-
mixed with filenames. Use --help to get a list of
the available languages and their default filename
extensions. The `auto' language can be used to re-
store automatic detection of language based on
filename extension. The `none' language may be
used to disable language parsing altogether; only
regexp matching is done in this case (see the
--regex option).
-o tagfile, --output=tagfile
Explicit name of file for tag table; overrides de-
fault `TAGS' or `tags'. (But ignored with -v or
-x.)
-r regexp, --regex=regexp
Make tags based on regexp matching for each line of
the files following this option, in addition to the
tags made with the standard parsing based on lan-
guage. May be freely intermixed with filenames and
the -R option. The regexps are cumulative, i.e.
each option will add to the previous ones. The
regexps are of the form:
/tagregexp[/nameregexp]/
where tagregexp is used to match the lines that
must be tagged. It should not match useless char-
acters. 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. gctags ignores regexps without
a nameregexp.
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 Cobol files:
--language=none --regex='/.......[a-zA-Z0-9-]+\./'
Tag Postscript files:
--language=none --regex='#/[^ \t{]+#/'
Tag TCL files (this last example shows the usage of
a tagregexp):
--lang=none --regex='/proc[ \t]+\([^ \t]+\)/\1/'
-R, --no-regex
Don't do any more regexp matching on the following
files. May be freely intermixed with filenames and
the --regex option.
-S, --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++.
-t, --typedefs
Record typedefs in C code as tags. Since this is
the default behaviour of etags, only gctags accepts
this option.
-T, --typedefs-and-c++
Generate tag entries for typedefs, struct, enum,
and union tags, and C++ member functions. Since
this is the default behaviour of etags, only gctags
accepts this 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 ex-
isting entries for the given files and then rewrit-
ing 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 gctags accepts this
option.
-v, --vgrind
Instead of generating a tag file, write index (in
vgrind format) to standard output. Only gctags ac-
cepts this option.
-w, --no-warn
Suppress warning messages about duplicate entries.
The etags program does not check for duplicate en-
tries, so this option is not allowed with it.
-x, --cxref
Instead of generating a tag file, write a cross
reference (in cxref format) to standard output.
Only gctags accepts this option.
-H, --help
Print usage information.
-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 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim
copies of this manual provided the copyright notice and
this permission notice are preserved on all copies.
Permission is granted to copy and distribute modified ver-
sions of this manual 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 manual into another language, under the above con-
ditions for modified versions, except that this permission
notice may be included in translations approved by the
Free Software Foundation instead of in the original En-
glish.