Provided by: xemacs21-bin_21.4.22-4ubuntu3_amd64 
NAME
etags, ctags - generate tag file for Emacs, vi
SYNOPSIS
etags [-aCDGImRVh] [-i file] [-l language]
[-o tagfile] [-r regexp]
[--append] [--no-defines] [--no-globals] [--include=file] [--ignore-indentation]
[--language=language] [--members] [--output=tagfile] [--regex=regexp] [--no-regex]
[--ignore-case-regex=regexp] [--help] [--version] file ...
ctags [-aCdgImRVh] [-BtTuvwx] [-l language]
[-o tagfile] [-r regexp]
[--append] [--backward-search] [--cxref] [--defines] [--forward-search] [--globals]
[--ignore-indentation] [--language=language] [--members] [--output=tagfile]
[--regex=regexp] [--ignore-case-regex=regexp] [--typedefs] [--typedefs-and-c++] [--update]
[--no-warn] [--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, LaTeX, Emacs Lisp/Common Lisp, makefiles, Pascal, Perl,
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. Files specified with absolute file names will be recorded with
absolute file names. 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.
-d, --defines
Create tag entries for C preprocessor constant definitions and enum constants, too.
This is the default behavior for etags.
-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. This is the default behavior for ctags.
-g, --globals
Create tag entries for global variables in C, C++, Objective C, Java, and Perl.
This is the default behavior for etags.
-G, --no-globals
Do not tag global variables. Typically this reduces the file size by one fourth.
This is the default behavior for ctags.
-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. This
options is only accepted by etags.
-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).
-m, --members
Create tag entries for variables that are members of structure-like constructs in
C++, Objective C, Java.
-M, --no-members
Do not tag member variables. This is the default behavior.
--packages-only
Only tag packages in Ada files.
-o tagfile, --output=tagfile
Explicit name of file for tag table; overrides default `TAGS' or `tags'. (But
ignored with -v or -x.)
-r regexp, --regex=regexp, --ignore-case-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 language.
When using --regex, case is significant, while it is not with --ignore-case-regex.
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 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, augmented with intervals of the form \{m,n\},
as in ed or grep.
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 restriciting it to match lines of files of
the specified language. Use etags --help to obtain a list of the recognised
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.
-t, --typedefs
Record typedefs in C code as tags. Since this is the default behaviour of etags,
only ctags 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 ctags 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 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.
-w, --no-warn
Suppress warning messages about duplicate entries. The etags program does not
check for duplicate entries, 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 ctags accepts this option.
-h, -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) 1999 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 versions 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 conditions for modified versions, except that this permission
notice may be included in translations approved by the Free Software Foundation instead of
in the original English.