*** In DOS, etags looks for file.cgz if it cannot find file.c.
+*** New option --ignore-case-regex is an alternative to --regex. It is now
+ possible to bind a regexp to a language, by prepending the regexp with
+ {lang}, where lang is one of the languages that `etags --help' prints
+ out. This feature is useful especially for regex files, where each
+ line contains a regular expression. The manual contains details.
+
*** In C and derived languages, etags creates tags for function
declarations when given the --declarations option.
*** In C++, tags are created for "operator". The tags have the form
-"operator+", without spaces between the keyword and the operator.
+"operator+", without spaces between the keyword and the operator.
*** New language Ada: tags are functions, procedures, packages, tasks, and
types.
*** .ss files are Scheme files.
-*** New option --ignore-case-regex is an alternative to --regex.
-
** Emacs now attempts to determine the initial language environment
and preferred and locale coding systems systematically from the
LC_ALL, LC_CTYPE, and LANG environment variables during startup.
@menu
* Tag Syntax:: Tag syntax for various types of code and text files.
* Create Tags Table:: Creating a tags table with @code{etags}.
-* Using Regexps:: Create arbitrary tags using regular expressions.
+* Etags Regexps:: Create arbitrary tags using regular expressions.
* Select Tags Table:: How to visit a tags table.
* Find Tag:: Commands to find the definition of a specific tag.
* Tags Search:: Using a tags table for searching and replacing.
is to tell @code{etags} to read the file names from its standard input,
by typing a dash in place of the file names, like this:
-@example
+@smallexample
find . -name "*.[chCH]" -print | etags -
-@end example
+@end smallexample
Use the option @samp{--language=@var{name}} to specify the language
explicitly. You can intermix these options with file names; each one
language from the file names and file contents. Specify
@samp{--language=none} to turn off language-specific processing
entirely; then @code{etags} recognizes tags by regexp matching alone
-(@pxref{Using Regexps}). @samp{etags --help} prints the list of the
-languages @code{etags} knows, and the file name rules for guessing the
-language.
+(@pxref{Etags Regexps}).
+
+ @samp{etags --help} prints the list of the languages @code{etags}
+knows, and the file name rules for guessing the language. It also prints
+a list of all the available @code{etags} options, together with a short
+explanation.
-@node Using Regexps
-@subsection Using Regexps
+@node Etags Regexps
+@subsection Etags Regexps
The @samp{--regex} option provides a general way of recognizing tags
based on regexp matching. You can freely intermix it with file names.
Each @samp{--regex} option adds to the preceding ones, and applies only
to the following files. The syntax is:
-@example
+@smallexample
--regex=/@var{tagregexp}[/@var{nameregexp}]/
-@end example
-
-or
-
-@example
---ignore-case-regex=/@var{tagregexp}[/@var{nameregexp}]/
-@end example
+@end smallexample
@noindent
-where @var{tagregexp} is used to match the lines to tag. The second
-form for the option syntax ignores the case when searching a match for
-the regular expression. @var{tagregexp} is always anchored, that is, it
-behaves as if preceded by @samp{^}. If you want to account for
-indentation, just match any initial number of blanks by beginning your
-regular expression with @samp{[ \t]*}. In the regular expressions,
-@samp{\} quotes the next character, and @samp{\t} stands for the tab
-character. Note that @code{etags} does not handle the other C escape
-sequences for special characters.
+where @var{tagregexp} is used to match the lines to tag. It is always
+anchored, that is, it behaves as if preceded by @samp{^}. If you want
+to account for indentation, just match any initial number of blanks by
+beginning your regular expression with @samp{[ \t]*}. In the regular
+expressions, @samp{\} quotes the next character, and @samp{\t} stands
+for the tab character. Note that @code{etags} does not handle the other
+C escape sequences for special characters.
@cindex interval operator (in regexps)
The syntax of regular expressions in @code{etags} is the same as in
accurately and to do completion on tag names more reliably. You can
find some examples below.
- The option @samp{--case-folded-regexp} (or @samp{-c}) si like
+ The option @samp{--ignore-case-regex} (or @samp{-c}) is like
@samp{--regex}, except that the regular expression provided will be
-matched with case folded, i.e. case-insensitively, which is appropriate
-for various programming languages.
+matched without regard to case, which is appropriate for various
+programming languages.
The @samp{-R} option deletes all the regexps defined with
@samp{--regex} options. It applies to the file names following it, as
you can see from the following example:
-@example
+@smallexample
etags --regex=/@var{reg1}/ voo.doo --regex=/@var{reg2}/ \
bar.ber -R --lang=lisp los.er
-@end example
+@end smallexample
@noindent
Here @code{etags} chooses the parsing language for @file{voo.doo} and
@file{bar.ber}. @code{etags} uses the Lisp tags rules, and no regexp
matching, to recognize tags in @file{los.er}.
- Here are some more examples. The regexps are quoted to protect them
-from shell interpretation.
+ A regular expression can be bound to a given language, by prepending
+it with @samp{@{lang@}}. When you do this, @code{etags} will use the
+regular expression only for files of that language. @samp{etags --help}
+prints the list of languages recognised by @code{etags}. The following
+example tags the @code{DEFVAR} macros in the Emacs source files.
+@code{etags} applies this regular expression to C files only:
-@itemize @bullet
-@item
-Tag the @code{DEFVAR} macros in the emacs source files:
+@smallexample
+--regex='@{c@}/[ \t]*DEFVAR_[A-Z_ \t(]+"\([^"]+\)"/'
+@end smallexample
+
+@noindent
+This feature is particularly useful when storing a list of regular
+expressions in a file. The following option syntax instructs
+@code{etags} to read two files of regular expressions. The regular
+expressions contained in the second file are matched without regard to
+case.
+
+@smallexample
+--regex=@@first-file --ignore-case-regex=@@second-file
+@end smallexample
+
+@noindent
+A regex file contains one regular expressions per line. Empty lines,
+and lines beginning with space or tab are ignored. When the first
+character in a line is @samp{@@}, @code{etags} assumes that the rest of
+the line is the name of a file of regular expressions. This means that
+such files can be nested. All the other lines are taken to be regular
+expressions. For example, one can create a file called
+@samp{emacs.tags} with the following contents (the first line in the
+file is a comment):
+
+@smallexample
+ -- This is for GNU Emacs source files
+@{c@}/[ \t]*DEFVAR_[A-Z_ \t(]+"\([^"]+\)"/\1/
+@end smallexample
+
+@noindent
+and then use it like this:
@smallexample
---regex='/[ \t]*DEFVAR_[A-Z_ \t(]+"\([^"]+\)"/'
+etags --regex=@@emacs.tags *.[ch] */*.[ch]
@end smallexample
+ Here are some more examples. The regexps are quoted to protect them
+from shell interpretation.
+
+@itemize @bullet
+
@item
Tag VHDL files (this example is a single long line, broken here for
formatting reasons):
@end smallexample
@end itemize
- For a list of the other available @code{etags} options, execute
-@code{etags --help}.
-
@node Select Tags Table
@subsection Selecting a Tags Table
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