Provided by: emacs25-common_25.2+1-6build1_all bug

NAME

       etags, ctags - generate tag file for Emacs, vi

SYNOPSIS

       etags [-aCDGIQRVh] [-i file] [-l language]
       [-o tagfile] [-r regexp] [--parse-stdin=file]
       [--append] [--no-defines] [--globals] [--no-globals] [--no-line-directive]
       [--include=file] [--ignore-indentation] [--language=language] [--members] [--no-members]
       [--output=tagfile] [--class-qualify] [--regex=regexp] [--no-regex] [--help] [--version]
       file ...

       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 ...

DESCRIPTION

       The  etags program is used to create a tag table file, in a format understood by emacs(1);
       the ctags 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, Forth, Go, HTML, LaTeX, Emacs  Lisp/Common  Lisp,  Lua,  Makefile,  Pascal,
       Perl,  Ruby,  PHP,  PostScript,  Python,  Prolog, Scheme and most assembler-like syntaxes.
       Both forms read the files specified on the command line, and write a tag table  (defaults:
       TAGS  for  etags,  tags for ctags) 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.  If the tag table is in /dev or is the standard
       output, however, the file names  are  made  relative  to  the  working  directory.   Files
       specified  with  absolute  file  names  will  be recorded with absolute 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.  Compressed files are supported using gzip,
       bzip2, and xz.  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
       filename extensions.

OPTIONS

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

       -a, --append
              Append to existing tag file.  (For vi-format tag files, see also --update.)

       -B, --backward-search
              Tag files written in the format expected by vi contain  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 ctags accepts this option.

       --declarations
              In  C and derived languages, create tags for function declarations, and create tags
              for extern variables unless --no-globals is used.  In Lisp, create tags for (defvar
              foo) declarations.

       -D, --no-defines
              Do  not  create  tag  entries  for  C  preprocessor  constant  definitions and enum
              constants.  This may make the tags file much  smaller  if  many  header  files  are
              tagged.

       --globals
              Create  tag entries for global variables in Perl and Makefile.  This is the default
              in C and derived languages.

       --no-globals
              Do not tag global variables in C and derived languages.  Typically this reduces the
              file size by one fourth.

       --no-line-directive
              Ignore #line preprocessor directives in C and derived languages.  The default is to
              honor those directives, and record the tags as if the  file  scanned  was  the  one
              named  in  the #line directive.  This switch is useful when the original file named
              by #line is no longer available.

       -i file, --include=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.  Only etags
              accepts this option.

       -I, --ignore-indentation
              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
              structure definition in C and C++.

       -l language, --language=language
              Parse the following files according to the given  language.   More  than  one  such
              options  may  be  intermixed  with  filenames.   Use  --help  to  get a list of the
              available languages and their default filename extensions.  The "auto" language can
              be  used  to  restore  automatic detection of language based on the file name.  The
              "none" language may be used to disable language  parsing  altogether;  only  regexp
              matching is done in this case (see the --regex option).

       --members
              Create  tag  entries for variables that are members of structure-like constructs in
              PHP.  This is the default for C and derived languages.

       --no-members
              Do not tag member variables.

       --packages-only
              Only tag packages in Ada files.

       --parse-stdin=file
              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 FILE.

        -Q, --class-qualify
              Qualify  tag  names  with  their  class  name  in  C++, ObjC, Java, and Perl.  This
              produces tag names of the form class::member for C++ and Perl, class(category)  for
              Objective  C, and class.member for Java.  For Objective C, this also produces class
              methods qualified with their arguments, as in foo:bar:baz:more.

       -o tagfile, --output=tagfile
              Explicit name of file for tag table; for  etags  only,  a  file  name  of  -  means
              standard output; overrides default TAGS or tags.  (But ignored with -v or -x.)

       -r regexp, --regex=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
                   @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.

       -R, --no-regex
              Don't do any more regexp matching on the following files.  May be freely intermixed
              with filenames and the --regex option.

       -u, --update
              Update  tag  entries  for  files specified on command line, leaving tag entries for
              other files in place.  Currently, this is  implemented  by  deleting  the  existing
              entries  for  the  given files and then rewriting 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 ctags accepts this option.

       -v, --vgrind
              Instead  of  generating  a  tag  file,  write  index (in vgrind format) to standard
              output.  Only ctags accepts this option.

       -x, --cxref
              Instead of generating a tag file, write a cross  reference  (in  cxref  format)  to
              standard output.  Only ctags accepts this option.

       -h, -H, --help
              Print  usage  information.  Followed by one or more --language=LANG prints detailed
              information about how tags are created for LANG.

       -V, --version
              Print the current version of the program (same as the version of the emacs etags is
              shipped with).

SEE ALSO

       "emacs" entry in info; GNU Emacs Manual, Richard Stallman.
       cxref(1), emacs(1), vgrind(1), vi(1).

COPYING

       Copyright (C) 1992, 1999, 2001-2017 Free Software Foundation, Inc.

       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.