Ubuntu Manpage: etags, ctags - generate tag file for Emacs, vi

Provided by: emacs-common_26.3+1-1ubuntu2_all

NAME

       etags, ctags - generate tag file for Emacs, vi

SYNOPSIS

       etags [-aCDGIQRVh] [-i file] [-l language]
       [-o tagfile] [-r regexp] [--parse-stdin=file]
       [--append] [--no-defines] [--globals] [--no-globals] [--no-line-directive]
       [--include=file] [--ignore-indentation] [--language=language] [--members] [--no-members]
       [--output=tagfile] [--class-qualify] [--regex=regexp] [--no-regex] [--help] [--version]
       file ...

       ctags [-aCdgIQRVh] [-BtTuvwx] [-l language]
       [-o tagfile] [-r regexp] [--parse-stdin=file]
       [--append] [--backward-search] [--cxref] [--no-defines] [--globals] [--no-globals]
       [--no-line-directive] [--ignore-indentation] [--language=language] [--members]
       [--no-members] [--class-qualify] [--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, Go, HTML, LaTeX, Emacs Lisp/Common Lisp, Lua, Makefile, Pascal,
Perl, Ruby, 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.

--no-line-directive
Ignore #line preprocessor directives in C and derived languages. The default is to
honor those directives, and record the tags as if the file scanned was the one
named in the #line directive. This switch is useful when the original file named
by #line is no longer available.

-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.

-Q, --class-qualify
Qualify tag names with their class name in C++, ObjC, Java, and Perl. This
produces tag names of the form class::member for C++ and Perl, class(category) for
Objective C, and class.member for Java. For Objective C, this also produces class
methods qualified with their arguments, as in foo:bar:baz:more.

-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 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).

COPYING

       Copyright 1992, 1999, 2001-2019 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.

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

SEE ALSO

COPYING