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 ...
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 VHDL files (this example is a single long line, broken here for
formatting reasons):
--language=none --regex='/[ \t]*\(ARCHITECTURE\|\
CONFIGURATION\) +[^ ]* +OF/' --regex='/[ \t]*\
\(ATTRIBUTE\|ENTITY\|FUNCTION\|PACKAGE\( BODY\)?\
\|PROCEDURE\|PROCESS\|TYPE\)[ \t]+\([^ \t(]+\)/\3/'
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.
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.