etags(1)

NAME
etags, ctags - 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 ... ctags [-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 `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, 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 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.

-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 ctags.

-D, --no-defines
    Do not create tag entries for C preprocessor definitions. This may make the tags file much smaller if many header files are tagged. This is the default behavior for ctags, 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 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 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 default `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 language. 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.
    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 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, --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 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.