.\" Copyright (c) 1992 Free Software Foundation
.\" See section COPYING for conditions for redistribution
.TH etags 1 "19apr1994" "GNU Tools" "GNU Tools"
.de BP
.sp
.ti -.2i
\(**
..
.SH NAME
etags, ctags \- generate tag file for Emacs, vi
.SH SYNOPSIS
.hy 0
.na
.B etags [\|\-aCDRSVh\|] [\|\-i \fIfile\fP\|] [\|\-l \fIlanguage\fP\|] [\|\-i \fIregexp\fP\|] [\|\-o \fItagfile\fP\|]
.br
[\|\-\-c++\|] [\|\-\-no\-defines\|] [\|\-\-ignore\-indentation\|]
[\|\-\-language=\fIlanguage\fP\|] [\|\-\-regex=\fIregexp\fP\|]
[\|\-\-no\-regexp\|] [\|\-\-help\|] [\|\-\-version\|]
[\|\-\-include=\fIfile\fP\|] [\|\-\-output=\fItagfile\fP\|]
[\|\-\-append\|] \fIfile\fP .\|.\|.
.B ctags [\|\-aCdRSVh\|] [\|\-BtTuvwx\|] [\|\-l \fIlanguage\fP\|]
.br
[\|\-i \fIregexp\fP\|] [\|\-o \fItagfile\fP\|]
[\|\-\-c++\|] [\|\-\-defines\|] [\|\-\-ignore\-indentation\|]
[\|\-\-no\-warn\|] [\|\-\-cxref\|] [\|\-\-backward\-search\|]
[\|\-\-forward\-search\|] [\|\-\-typedefs\|] [\|\-\-typedefs\-and\-c++\|]
[\|\-\-language=\fIlanguage\fP\|] [\|\-\-regex=\fIregexp\fP\|]
[\|\-\-help\|] [\|\-\-version\|]
.br
[\|\-\-output=\fItagfile\fP\|] [\|\-\-append\|] [\|\-\-update\|] \fIfile\fP .\|.\|.
.ad b
.hy 1
.SH DESCRIPTION
The `\|\fBetags\fP\|' program is used to create a tag table file, in a format
understood by
.BR emacs ( 1 )\c
\&; the `\|\fBctags\fP\|' program is used to create a similar table in a
format understood by
.BR vi ( 1 )\c
\&. 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 \fBetags\fP, `\|tags\|' for
\fBctags\fP) 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.
.SH OPTIONS
Some options make sense only for the \fBvi\fP style tag files produced
by ctags;
\fBetags\fP does not recognize them.
The programs accept unambiguous abbreviations for long option names.
.TP
.B \-a, \-\-append
Append to existing tag file. (For vi-format tag files, see also
\fB\-\-update\fP.)
.TP
.B \-B, \-\-backward\-search
Tag files written in the format expected by \fBvi\fP contain regular
expression search instructions; the \fB\-B\fP option writes them using
the delimiter `\|\fB?\fP\|', to search \fIbackwards\fP through files.
The default is to use the delimiter `\|\fB/\fP\|', to search \fIforwards\fP
through files.
Only \fBctags\fP accepts this option.
.TP
.B \-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.
.TP
.B \-d, \-\-defines
Create tag entries for C preprocessor definitions, too. This is the
default behavior for \fBetags\fP, so this option is only accepted
by \fBctags\fP.
.TP
.B \-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 \fBctags\fP, so this option is only
accepted by \fBetags\fP.
.TP
\fB\-l\fP \fIlanguage\fP, \fB\-\-language=\fIlanguage\fP
Parse the following files according to the given language. More than
one such options may be intermixed with filenames. Use \fB\-\-help\fP
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 \fB\-\-regex\fP option).
.TP
\fB\-o\fP \fItagfile\fP, \fB\-\-output=\fItagfile\fP
Explicit name of file for tag table; overrides default `\|TAGS\|' or
`\|tags\|'. (But ignored with \fB\-v\fP or \fB\-x\fP.)
.TP
\fB\-r\fP \fIregexp\fP, \fB\-\-regex=\fIregexp\fP
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 \fB\-R\fP option. The regexps are cumulative, i.e. each
option will add to the previous ones. The regexps are of the form:
.br
\fB/\fP\fItagregexp\fP[\fB/\fP\fInameregexp\fP]\fB/\fP
.br
where \fItagregexp\fP 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
\fItagregexp\fP, it may be useful to add a \fInameregexp\fP, to
narrow down the tag scope. \fBctags\fP ignores regexps without a
\fInameregexp\fP.
.br
Here are some examples. All the regexps are quoted to protect them
from shell interpretation.
.br
Tag the DEFVAR macros in the emacs source files:
.br
\fI\-\-regex\='/[ \\t]*DEFVAR_[A-Z_ \\t(]+"\\([^"]+\\)"\/'\fP
.br
Tag VHDL files (this example is a single long line, broken here for
formatting reasons):
.br
\fI\-\-language\=none\ \-\-regex='/[\ \\t]*\\(ARCHITECTURE\\|\\
CONFIGURATION\\)\ +[^\ ]*\ +OF/'\ \-\-regex\='/[\ \\t]*\\
\\(ATTRIBUTE\\|ENTITY\\|FUNCTION\\|PACKAGE\\(\ BODY\\)?\\
\\|PROCEDURE\\|PROCESS\\|TYPE\\)[\ \\t]+\\([^\ \\t(]+\\)/\\3/'\fP
.br
Tag Cobol files:
.br
\fI\-\-language\=none \-\-regex\='/.......[a\-zA\-Z0\-9\-]+\\./'\fP
.br
Tag Postscript files:
.br
\fI\-\-language\=none \-\-regex\='#/[^\ \\t{]+#/'\fP
.br
Tag TCL files (this last example shows the usage of a \fItagregexp\fP):
.br
\fI\-\-lang\=none \-\-regex\='/proc[\ \\t]+\\([^\ \\t]+\\)/\\1/'\fP
.TP
.B \-R, \-\-no\-regex
Don't do any more regexp matching on the following files. May be
freely intermixed with filenames and the \fB\-\-regex\fP option.
.TP
.B \-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++.
.TP
.B \-t, \-\-typedefs
Record typedefs in C code as tags. Since this is the default behaviour
of \fBetags\fP, only \fBctags\fP accepts this option.
.TP
.B \-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 \fBetags\fP, only \fBctags\fP accepts this option.
.TP
.B \-u, \-\-update
Update tag entries for \fIfiles\fP 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 \fBctags\fP accepts this option.
.TP
.B \-v, \-\-vgrind
Instead of generating a tag file, write index (in \fBvgrind\fP format)
to standard output. Only \fBctags\fP accepts this option.
.TP
.B \-w, \-\-no\-warn
Suppress warning messages about duplicate entries. The \fBetags\fP
program does not check for duplicate entries, so this option is not
allowed with it.
.TP
.B \-x, \-\-cxref
Instead of generating a tag file, write a cross reference (in
\fBcxref\fP format) to standard output. Only \fBctags\fP accepts this option.
.TP
.B \-H, \-\-help
Print usage information.
.TP
.B \-V, \-\-version
Print the current version of the program (same as the version of the
emacs \fBetags\fP is shipped with).
.SH "SEE ALSO"
`\|\fBemacs\fP\|' entry in \fBinfo\fP; \fIGNU Emacs Manual\fP, Richard
Stallman.
.br
.BR cxref ( 1 ),
.BR emacs ( 1 ),
.BR vgrind ( 1 ),
.BR vi ( 1 ).
.SH COPYING
Copyright (c) 1992 Free Software Foundation, Inc.
.PP
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.
.PP
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.
.PP
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.