1:gnuctags

etags [-aCDGImRVh] [-i file] [-l language] [-o tagfile] [-r regexp] [--parse-stdin=file]
[--append] [--no-defines] [--no-globals] [--include=file] [--ignore-indentation] [--language=language] [--members] [--output=tagfile] [--regex=regexp] [--no-regex] [--help] [--version] file

gnuctags [-aCdgImRVh] [-BtTuvwx] [-l language] [-o tagfile] [-r regexp] [--parse-stdin=file]
[--append] [--backward-search] [--cxref] [--defines] [--forward-search] [--globals] [--ignore-indentation] [--language=language] [--members] [--output=tagfile] [--regex=regexp] [--typedefs] [--typedefs-and-c++] [--update] [--no-warn]

The etags program is used to create a tag table file, in a format understood by emacs(1); the gnuctags 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, HTML, LaTeX, Emacs Lisp/Common Lisp, makefiles, Pascal, Perl, PHP, Postscript, Python, Prolog, Scheme and most as- sembler-like syntaxes. Both forms read the files speci- fied on the command line, and write a tag table (defaults: TAGS for etags, tags for gnuctags) 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 speci- fied with absolute file names will be recorded with abso- lute 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. 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

Some options make sense only for the vi style tag files produced by gnuctags; etags does not recognize them. The programs accept unambiguous abbreviations for long

Append to existing tag file. (For vi-format tag

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 gnuctags accepts this

In C and derived languages, create tags for func- tion declarations, and create tags for extern vari- ables unless

Create tag entries for C preprocessor constant def- initions and enum constants, too. This is the de- fault behavior for

Do not create tag entries for C preprocessor con- stant definitions and enum constants. This may make the tags file much smaller if many header files are tagged. This is the

Create tag entries for global variables in C, C++, Objective C, Java, and Perl. This is the default behavior for

Do not tag global variables. Typically this re- duces the file size by one fourth. This is the de- fault behavior for

-i 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

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

-l 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 the file name. The `none' language may be used to dis- able language parsing altogether; only regexp matching is done in this case (see the --regex op-

Create tag entries for variables that are members of structure-like constructs in C++, Objective C,

Do not tag member variables. This is the default

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

-o tagfile,

Explicit name of file for tag table; overrides de- fault TAGS or tags. (But ignored with -v or

-r 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

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 un- avoidably matched by tagregexp, it may be useful to add a nameregexp, to narrow down the tag scope. gnuctags 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 respec- tively stand for the ASCII characters BEL, BS, DEL, ESC, FF, NL, CR, TAB, VT.
The modifiers are a sequence of 0 or more charac- ters 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 lan- guage, 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

Here are some examples. All the regexps are quoted to

Tag the DEFVAR macros in the emacs source files:
--regex='/[ t]*DEFVAR_[A-Z_

Tag VHDL files (this example is a single long line, broken here for formatting reasons):
--language=none --regex='/[ t]* CONFIGURATION) +[^ ]* +OF/' --regex='/[ t]*\ BODY)?\ |PROCEDURE|PROCESS|TYPE)[ t]+

Tag TCL files (this last example shows the usage of a tagregexp):

A regexp can be preceded by {lang}, thus restrict- ing 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 be- ginning with @ are references to regex files whose name follows the @ sign. Other lines are consid- ered regular expressions like those following --regex.
For example, the command
etags --regex=@regex.file *.c
reads the regexes contained in the file

Don't do any more regexp matching on the following files. May be freely intermixed with filenames and the

Record typedefs in C code as tags. Since this is the default behavior of etags, only gnuctags ac- cepts

Generate tag entries for typedefs, struct, enum, and union tags, and C++ member functions. Since this is the default behavior of etags, only gnuc- tags accepts

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

Instead of generating a tag file, write index (in vgrind format) to standard output. Only

Suppress warning messages about duplicate entries. The etags program does not check for duplicate en- tries,

Instead of generating a tag file, write a cross reference (in cxref format) to standard output. Only

Print the current version of the program (same as the version of the emacs etags is shipped

`emacs' entry in info; GNU Emacs Manual, Richard Stallman.
ctags(1), cxref(1), emacs(1), gnuctags(1),

Copyright 1999, 2001 Free Software Foundation,

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