1etags(1) GNU Tools etags(1)
2
6 etags, ctags - generate tag file for Emacs, vi
7
9 etags [-aCDGIRVh] [-i file] [-l language]
10 [-o tagfile] [-r regexp] [--parse-stdin=file]
11 [--append] [--no-defines] [--globals] [--no-globals] [--include=file]
12 [--ignore-indentation] [--language=language] [--members] [--no-members]
13 [--output=tagfile] [--regex=regexp] [--no-regex] [--help] [--version]
14 file ...
15 ctags [-aCdgIRVh] [-BtTuvwx] [-l language]
17 [-o tagfile] [-r regexp] [--parse-stdin=file]
18 [--append] [--backward-search] [--cxref] [--no-defines] [--globals]
19 [--no-globals] [--ignore-indentation] [--language=language] [--members]
20 [--no-members] [--output=tagfile] [--regex=regexp] [--update] [--help]
21 [--version] file ...
22
24 The etags program is used to create a tag table file, in a format un‐
25 derstood by emacs(1); the ctags program is used to create a similar ta‐
26 ble in a format understood by vi(1). Both forms of the program under‐
27 stand the syntax of C, Objective C, C++, Java, Fortran, Ada, Cobol, Er‐
28 lang, Forth, HTML, LaTeX, Emacs Lisp/Common Lisp, Lua, Makefile, Pas‐
29 cal, Perl, PHP, Postscript, Python, Prolog, Scheme and most assem‐
30 bler-like syntaxes. Both forms read the files specified on the command
31 line, and write a tag table (defaults: TAGS for etags, tags for ctags)
32 in the current working directory. Files specified with relative file
33 names will be recorded in the tag table with file names relative to the
34 directory where the tag table resides. If the tag table is in /dev or
35 is the standard output, however, the file names are made relative to
36 the working directory. Files specified with absolute file names will
37 be recorded with absolute file names. Files generated from a source
38 file--like a C file generated from a source Cweb file--will be recorded
39 with the name of the source file. Compressed files are supported using
40 gzip and bzip2. The programs recognize the language used in an input
41 file based on its file name and contents. The --language switch can be
42 used to force parsing of the file names following the switch according
43 to the given language, overriding guesses based on filename extensions.
44
46 Some options make sense only for the vi style tag files produced by
47 ctags; etags does not recognize them. The programs accept unambiguous
48 abbreviations for long option names.
49 -a, --append
51 Append to existing tag file. (For vi-format tag files, see also
52 --update.)
53 -B, --backward-search
55 Tag files written in the format expected by vi contain regular
56 expression search instructions; the -B option writes them using
57 the delimiter `?', to search backwards through files. The de‐
58 fault is to use the delimiter `/', to search forwards through
59 files. Only ctags accepts this option.
60 --declarations
62 In C and derived languages, create tags for function declara‐
63 tions, and create tags for extern variables unless --no-globals
64 is used.
65 -D, --no-defines
67 Do not create tag entries for C preprocessor constant defini‐
68 tions and enum constants. This may make the tags file much
69 smaller if many header files are tagged.
70 --globals
72 Create tag entries for global variables in Perl and Makefile.
73 This is the default in C and derived languages.
74 --no-globals
76 Do not tag global variables in C and derived languages. Typi‐
77 cally this reduces the file size by one fourth.
78 -i file, --include=file
80 Include a note in the tag file indicating that, when searching
81 for a tag, one should also consult the tags file file after
82 checking the current file. Only etags accepts this option.
83 -I, --ignore-indentation
85 Don't rely on indentation as much as we normally do. Currently,
86 this means not to assume that a closing brace in the first col‐
87 umn is the final brace of a function or structure definition in
88 C and C++.
89 -l language, --language=language
91 Parse the following files according to the given language. More
92 than one such options may be intermixed with filenames. Use
93 --help to get a list of the available languages and their de‐
94 fault filename extensions. The `auto' language can be used to
95 restore automatic detection of language based on the file name.
96 The `none' language may be used to disable language parsing al‐
97 together; only regexp matching is done in this case (see the
98 --regex option).
99 --members
101 Create tag entries for variables that are members of structure-
102 like constructs in PHP. This is the default for C and derived
103 languages.
104 --no-members
106 Do not tag member variables.
107 --packages-only
109 Only tag packages in Ada files.
110 --parse-stdin=file
112 May be used (only once) in place of a file name on the command
113 line. etags will read from standard input and mark the produced
114 tags as belonging to the file FILE.
115 -o tagfile, --output=tagfile
117 Explicit name of file for tag table; for etags only, a file name
118 of - means standard output; overrides default TAGS or tags.
119 (But ignored with -v or -x.)
120 -r regexp, --regex=regexp
122 Make tags based on regexp matching for the files following this
124 option, in addition to the tags made with the standard parsing
125 based on language. May be freely intermixed with filenames and
126 the -R option. The regexps are cumulative, i.e. each such op‐
127 tion will add to the previous ones. The regexps are of one of
128 the forms:
129 [{language}]/tagregexp/[nameregexp/]modifiers
130 @regexfile
131 where tagregexp is used to match the tag. It should not match
133 useless characters. If the match is such that more characters
134 than needed are unavoidably matched by tagregexp, it may be use‐
135 ful to add a nameregexp, to narrow down the tag scope. ctags
136 ignores regexps without a nameregexp. The syntax of regexps is
137 the same as in emacs. The following character escape sequences
138 are supported: \a, \b, \d, \e, \f, \n, \r, \t, \v, which respec‐
139 tively stand for the ASCII characters BEL, BS, DEL, ESC, FF, NL,
140 CR, TAB, VT.
141 The modifiers are a sequence of 0 or more characters among i,
142 which means to ignore case when matching; m, which means that
143 the tagregexp will be matched against the whole file contents at
144 once, rather than line by line, and the matching sequence can
145 match multiple lines; and s, which implies m and means that the
146 dot character in tagregexp matches the newline char as well.
147 The separator, which is / in the examples, can be any character
148 different from space, tab, braces and @. If the separator char‐
149 acter is needed inside the regular expression, it must be quoted
150 by preceding it with \.
151 The optional {language} prefix means that the tag should be cre‐
152 ated only for files of language language, and ignored otherwise.
153 This is particularly useful when storing many predefined regexps
154 in a file.
155 In its second form, regexfile is the name of a file that con‐
156 tains a number of arguments to the --regex= option, one per
157 line. Lines beginning with a space or tab are assumed to be
158 comments, and ignored.
159 Here are some examples. All the regexps are quoted to protect
161 them from shell interpretation.
162 Tag the DEFVAR macros in the emacs source files:
164 --regex='/[ \t]*DEFVAR_[A-Z_ \t(]+"\([^"]+\)"/'
165 Tag VHDL files (this example is a single long line, broken here
167 for formatting reasons):
168 --language=none --regex='/[ \t]*\(ARCHITECTURE\|\ CONFIGURA‐
169 TION\) +[^ ]* +OF/' --regex='/[ \t]*\ \(ATTRIBUTE\|ENTITY\|FUNC‐
170 TION\|PACKAGE\( BODY\)?\ \|PROCE‐
171 DURE\|PROCESS\|TYPE\)[ \t]+\([^ \t(]+\)/\3/'
172 Tag TCL files (this last example shows the usage of a tagreg‐
174 exp):
175 --lang=none --regex='/proc[ \t]+\([^ \t]+\)/\1/'
176 A regexp can be preceded by {lang}, thus restricting it to match
178 lines of files of the specified language. Use etags --help to
179 obtain a list of the recognized languages. This feature is par‐
180 ticularly useful inside regex files. A regex file contains one
181 regex per line. Empty lines, and those lines beginning with
182 space or tab are ignored. Lines beginning with @ are references
183 to regex files whose name follows the @ sign. Other lines are
184 considered regular expressions like those following --regex.
185 For example, the command
186 etags --regex=@regex.file *.c
187 reads the regexes contained in the file regex.file.
188 -R, --no-regex
190 Don't do any more regexp matching on the following files. May
191 be freely intermixed with filenames and the --regex option.
192 -u, --update
194 Update tag entries for files specified on command line, leaving
195 tag entries for other files in place. Currently, this is imple‐
196 mented by deleting the existing entries for the given files and
197 then rewriting the new entries at the end of the tags file. It
198 is often faster to simply rebuild the entire tag file than to
199 use this. Only ctags accepts this option.
200 -v, --vgrind
202 Instead of generating a tag file, write index (in vgrind format)
203 to standard output. Only ctags accepts this option.
204 -x, --cxref
206 Instead of generating a tag file, write a cross reference (in
207 cxref format) to standard output. Only ctags accepts this op‐
208 tion.
209 -h, -H, --help
211 Print usage information. Followed by one or more --lan‐
212 guage=LANG prints detailed information about how tags are creat‐
213 ed for LANG.
214 -V, --version
216 Print the current version of the program (same as the version of
217 the emacs etags is shipped with).
218
221 `emacs' entry in info; GNU Emacs Manual, Richard Stallman.
222 cxref(1), emacs(1), vgrind(1), vi(1).
223
226 Copyright (C) 1992, 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
227 2008, 2009 Free Software Foundation, Inc.
228 Permission is granted to make and distribute verbatim copies of this
230 document provided the copyright notice and this permission notice are
231 preserved on all copies.
232 Permission is granted to copy and distribute modified versions of this
234 document under the conditions for verbatim copying, provided that the
235 entire resulting derived work is distributed under the terms of a per‐
236 mission notice identical to this one.
237 Permission is granted to copy and distribute translations of this docu‐
239 ment into another language, under the above conditions for modified
240 versions, except that this permission notice may be stated in a trans‐
241 lation approved by the Free Software Foundation.
242GNU Tools 23nov2001 etags(1)