1etags(1)                           GNU Tools                          etags(1)
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NAME

6       etags, ctags - generate tag file for Emacs, vi
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SYNOPSIS

9       etags [-aCDGIRVh] [-i file] [-l language]
10       [-o tagfile] [-r regexp] [--parse-stdin=file]
11       [--append] [--no-defines] [--no-globals] [--include=file]
12       [--ignore-indentation] [--language=language] [--no-members]
13       [--output=tagfile] [--regex=regexp] [--no-regex] [--help] [--version]
14       file ...
15
16       ctags [-aCdgIRVh] [-BtTuvwx] [-l language]
17       [-o tagfile] [-r regexp] [--parse-stdin=file]
18       [--append] [--backward-search] [--cxref] [--defines] [--forward-search]
19       [--globals] [--ignore-indentation] [--language=language] [--members]
20       [--output=tagfile] [--regex=regexp] [--typedefs] [--typedefs-and-c++]
21       [--update] [--help] [--version] file ...
22

DESCRIPTION

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, HTML, LaTeX, Emacs Lisp/Common Lisp, Lua, makefile, Pascal, Perl,
29       PHP, Postscript, Python, Prolog, Scheme and most assembler-like syntax‐
30       es.  Both forms read the files specified on the command line, and write
31       a tag table (defaults: TAGS for etags, tags for ctags) in  the  current
32       working  directory.   Files  specified with relative file names will be
33       recorded in the tag table with file names  relative  to  the  directory
34       where the tag table resides.  If the tag table is in /dev, however, the
35       file names are made relative to the working directory.  Files specified
36       with  absolute  file  names  will be recorded with absolute file names.
37       Files generated from a source file--like a  C  file  generated  from  a
38       source  Cweb  file--will  be recorded with the name of the source file.
39       The programs recognize the language used in an input file based on  its
40       file  name  and  contents.   The --language switch can be used to force
41       parsing of the file names following the switch according to  the  given
42       language, overriding guesses based on filename extensions.
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OPTIONS

45       Some  options  make  sense  only for the vi style tag files produced by
46       ctags; etags does not recognize them.  The programs accept  unambiguous
47       abbreviations for long option names.
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49       -a, --append
50              Append to existing tag file.  (For vi-format tag files, see also
51              --update.)
52
53       -B, --backward-search
54              Tag files written in the format expected by vi  contain  regular
55              expression  search instructions; the -B option writes them using
56              the delimiter `?', to search backwards through files.   The  de‐
57              fault  is  to  use the delimiter `/', to search forwards through
58              files.  Only ctags accepts this option.
59
60       --declarations
61              In C and derived languages, create tags  for  function  declara‐
62              tions,  and create tags for extern variables unless --no-globals
63              is used.
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65       -d, --defines
66              Create tag entries for C preprocessor constant  definitions  and
67              enum  constants,  too.   Since  this  is the default behavior of
68              etags, only ctags accepts this option.
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70       -D, --no-defines
71              Do not create tag entries for C  preprocessor  constant  defini‐
72              tions  and  enum  constants.   This  may make the tags file much
73              smaller if many header files are tagged.  Since this is the  de‐
74              fault behavior of ctags, only etags accepts this option.
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76       --globals
77              Create  tag entries for global variables in C, C++, Objective C,
78              Java, and Perl.  Since this is the default  behavior  of  etags,
79              only ctags accepts this option.
80
81       --no-globals
82              Do  not  tag  global variables.  Typically this reduces the file
83              size by one fourth.  Since  this  is  the  default  behavior  of
84              ctags, only etags accepts this option.
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86       -i file, --include=file
87              Include  a  note in the tag file indicating that, when searching
88              for a tag, one should also consult  the  tags  file  file  after
89              checking the current file.  Only etags accepts this option.
90
91       -I, --ignore-indentation
92              Don't rely on indentation as much as we normally do.  Currently,
93              this means not to assume that a closing brace in the first  col‐
94              umn  is the final brace of a function or structure definition in
95              C and C++.
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97       -l language, --language=language
98              Parse the following files according to the given language.  More
99              than  one  such  options  may be intermixed with filenames.  Use
100              --help to get a list of the available languages  and  their  de‐
101              fault  filename  extensions.  The `auto' language can be used to
102              restore automatic detection of language based on the file  name.
103              The  `none' language may be used to disable language parsing al‐
104              together; only regexp matching is done in  this  case  (see  the
105              --regex option).
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107       --members
108              Create  tag entries for variables that are members of structure-
109              like constructs in C++, Objective C, Java.  This is the  default
110              for etags.
111
112       --no-members
113              Do not tag member variables.  This is the default for ctags.
114
115       --packages-only
116              Only tag packages in Ada files.
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118       --parse-stdin=file
119              May  be  used (only once) in place of a file name on the command
120              line.  etags will read from standard input and mark the produced
121              tags as belonging to the file FILE.
122
123       -o tagfile, --output=tagfile
124              Explicit  name  of file for tag table; overrides default TAGS or
125              tags.   (But ignored with -v or -x.)
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127       -r regexp, --regex=regexp
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129              Make tags based on regexp matching for the files following  this
130              option,  in  addition to the tags made with the standard parsing
131              based on language. May be freely intermixed with  filenames  and
132              the  -R  option.  The regexps are cumulative, i.e. each such op‐
133              tion will add to the previous ones.  The regexps are of  one  of
134              the forms:
135                   [{language}]/tagregexp/[nameregexp/]modifiers
136                   @regexfile
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138              where  tagregexp  is used to match the tag.  It should not match
139              useless characters.  If the match is such that  more  characters
140              than needed are unavoidably matched by tagregexp, it may be use‐
141              ful to add a nameregexp, to narrow down the  tag  scope.   ctags
142              ignores  regexps without a nameregexp.  The syntax of regexps is
143              the same as in emacs.  The following character escape  sequences
144              are supported: \a, \b, \d, \e, \f, \n, \r, \t, \v, which respec‐
145              tively stand for the ASCII characters BEL, BS, DEL, ESC, FF, NL,
146              CR, TAB, VT.
147              The  modifiers  are  a sequence of 0 or more characters among i,
148              which means to ignore case when matching; m,  which  means  that
149              the tagregexp will be matched against the whole file contents at
150              once, rather than line by line, and the  matching  sequence  can
151              match  multiple lines; and s, which implies m and means that the
152              dot character in tagregexp matches the newline char as well.
153              The separator, which is / in the examples, can be any  character
154              different from space, tab, braces and @.  If the separator char‐
155              acter is needed inside the regular expression, it must be quoted
156              by preceding it with \.
157              The optional {language} prefix means that the tag should be cre‐
158              ated only for files of language language, and ignored otherwise.
159              This is particularly useful when storing many predefined regexps
160              in a file.
161              In its second form, regexfile is the name of a  file  that  con‐
162              tains  a  number  of  arguments  to the --regex= option, one per
163              line.  Lines beginning with a space or tab  are  assumed  to  be
164              comments, and ignored.
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166              Here  are  some examples.  All the regexps are quoted to protect
167              them from shell interpretation.
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169              Tag the DEFVAR macros in the emacs source files:
170              --regex='/[ \t]*DEFVAR_[A-Z_ \t(]+"\([^"]+\)"/'
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172              Tag VHDL files (this example is a single long line, broken  here
173              for formatting reasons):
174              --language=none --regex='/[ \t]*\(ARCHITECTURE\|\     CONFIGURA‐
175              TION\) +[^ ]* +OF/' --regex='/[ \t]*\ \(ATTRIBUTE\|ENTITY\|FUNC‐
176              TION\|PACKAGE\( BODY\)?\                                \|PROCE‐
177              DURE\|PROCESS\|TYPE\)[ \t]+\([^ \t(]+\)/\3/'
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179              Tag TCL files (this last example shows the usage  of  a  tagreg‐
180              exp):
181              --lang=none --regex='/proc[ \t]+\([^ \t]+\)/\1/'
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183              A regexp can be preceded by {lang}, thus restricting it to match
184              lines of files of the specified language.  Use etags  --help  to
185              obtain a list of the recognised languages.  This feature is par‐
186              ticularly useful inside regex files.  A regex file contains  one
187              regex  per  line.   Empty  lines, and those lines beginning with
188              space or tab are ignored.  Lines beginning with @ are references
189              to  regex  files whose name follows the @ sign.  Other lines are
190              considered regular expressions like those following --regex.
191              For example, the command
192              etags --regex=@regex.file *.c
193              reads the regexes contained in the file regex.file.
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195       -R, --no-regex
196              Don't do any more regexp matching on the following  files.   May
197              be freely intermixed with filenames and the --regex option.
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199       -t, --typedefs
200              Record  typedefs  in  C code as tags.  Since this is the default
201              behavior of etags, only ctags accepts this option.
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203       -T, --typedefs-and-c++
204              Generate tag entries for typedefs, struct, enum, and union tags,
205              and C++ member functions.  Since this is the default behavior of
206              etags, only ctags accepts this option.
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208       -u, --update
209              Update tag entries for files specified on command line,  leaving
210              tag entries for other files in place.  Currently, this is imple‐
211              mented by deleting the existing entries for the given files  and
212              then  rewriting the new entries at the end of the tags file.  It
213              is often faster to simply rebuild the entire tag  file  than  to
214              use this.  Only ctags accepts this option.
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216       -v, --vgrind
217              Instead of generating a tag file, write index (in vgrind format)
218              to standard output.  Only ctags accepts this option.
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220       -x, --cxref
221              Instead of generating a tag file, write a  cross  reference  (in
222              cxref  format)  to standard output.  Only ctags accepts this op‐
223              tion.
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225       -h, -H, --help
226              Print  usage  information.   Followed  by  one  or  more  --lan‐
227              guage=LANG prints detailed information about how tags are creat‐
228              ed for LANG.
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230       -V, --version
231              Print the current version of the program (same as the version of
232              the emacs etags is shipped with).
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SEE ALSO

236       `emacs' entry in info; GNU Emacs Manual, Richard Stallman.
237       cxref(1), emacs(1), vgrind(1), vi(1).
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COPYING

241       Copyright  (c)  1999,  2001,  2002,  2003, 2004, 2005, 2006, 2007  Free
242       Software Foundation, Inc.
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244       Permission is granted to make and distribute verbatim  copies  of  this
245       document  provided  the copyright notice and this permission notice are
246       preserved on all copies.
247
248       Permission is granted to copy and distribute modified versions of  this
249       document  under  the conditions for verbatim copying, provided that the
250       entire resulting derived work is distributed under the terms of a  per‐
251       mission notice identical to this one.
252
253       Permission is granted to copy and distribute translations of this docu‐
254       ment into another language, under the  above  conditions  for  modified
255       versions,  except that this permission notice may be stated in a trans‐
256       lation approved by the Free Software Foundation.
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261GNU Tools                          23nov2001                          etags(1)
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