ctags(1)                 USER COMMANDS                   ctags(1)



NAME
     ctags - create a tags file for use with vi

SYNOPSIS
     ctags [ -aBFtuvwx ] [ -f tagsfile ] filename...

DESCRIPTION
     ctags makes a tags file for ex(1) from the specified C, Pas-
     cal,  FORTRAN, YACC, and LEX sources.  A tags file gives the
     locations of specified objects (in this case  functions  and
     typedefs)  in  a group of files.  Each line of the tags file
     contains the object name, the file in which it  is  defined,
     and  an  address  specification  for  the object definition.
     Functions are searched with a pattern, typedefs with a  line
     number. Specifiers are given in separate fields on the line,
     separated by SPACE or TAB characters.  Using the tags  file,
     ex can quickly find these objects definitions.

     Normally ctags places the tag descriptions in a file  called
     tags; this may be overridden with the -f option.

     Files with names ending in .c or .h  are  assumed  to  be  C
     source files and are searched for C routine and macro defin-
     itions.  Files with names ending in .y  are  assumed  to  be
     YACC  source  files.   Files  with  names  ending  in .l are
     assumed to be LEX files.  Others are first examined  to  see
     if  they  contain any Pascal or FORTRAN routine definitions;
     if not, they are processed again looking for C definitions.

     The tag main is treated specially in C  programs.   The  tag
     formed is created by prepending M to filename, with a trail-
     ing .c removed, if any, and leading pathname components also
     removed.  This  makes  use of ctags practical in directories
     with more than one program.

     The following options are available:

     -a   Append output to an existing tags file.

     -B   Use backward searching patterns (?...?).

     -F   Use forward searching patterns (/.../) (default).

     -t   Create tags for typedefs.

     -u   Update the specified files in tags, that is, all refer-
          ences  to  them  are  deleted,  and  the new values are
          appended to the file.  Beware: this  option  is  imple-
          mented  in  a  way  which is rather slow; it is usually
          faster to simply rebuild the tags file.

     -v   Produce on the standard output  an  index  listing  the



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ctags(1)                 USER COMMANDS                   ctags(1)



          function  name, file name, and page number (assuming 64
          line pages).  Since the output will be sorted into lex-
          icographic  order,  it may be desired to run the output
          through sort -f.

     -w   Suppress warning diagnostics.

     -x   Produce a list of object names,  the  line  number  and
          file name on which each is defined, as well as the text
          of that line and prints this on  the  standard  output.
          This  is  a simple index which can be printed out as an
          off-line readable function index.

FILES
     tags                output tags file

USAGE
     The -v option is mainly used with vgrind which will be  part
     of the optional BSD Compatibility Package.

SEE ALSO
     ex(1), vgrind(1), vi(1)

NOTES
     Recognition of functions,  subroutines  and  procedures  for
     FORTRAN  and  Pascal is done is a very simpleminded way.  No
     attempt is made to deal with block structure;  if  you  have
     two Pascal procedures in different blocks with the same name
     you lose.

     The method of deciding whether to look for C or  Pascal  and
     FORTRAN functions is a hack.

     ctags does not know about #ifdefs.

     ctags should know about Pascal types.  Relies on  the  input
     being well formed to detect typedefs.  Use of -tx shows only
     the last line of typedefs.

















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