ctags

PURPOSE

     Makes a  file of  tags to help  locate objects  in source
     files.

SYNOPSIS
     ctags [ -auwx ] name ...


DESCRIPTION

     The ctags command makes a tags file for ex and vi editors
     from the  specified C, Pascal, and  FORTRAN source files.
     A tags file gives the  locations of specified objects (in
     this case functions)  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.  Specifiers are given  in separate fields on the
     line, separated by blanks or  tabs.  Using the tags file,
     ex and vi can quickly find these object definitions.

     If a file name ends in .c or  .h, it is assumed to be a C
     source file and is searched for C routine and macro defi-
     nitions.   Others  are  first  examined to  see  if  they
     contain  any Pascal  or FORTRAN  routine definitions;  if
     not, they are processed again for C definitions.

     The tag main is treated specially in C programs.  The tag
     formed  is  created by  prefixing  M  to the  file  name,
     removing a trailing .c (if any), and removing the leading
     path name components.  This  makes use of ctags practical
     in directories with more than one program.

     Notes:

     1.  Recognitions  of the  keywords function,  subroutine,
         and procedure in FORTRAN and Pascal code is performed
         in a very  simple-minded way.  No attempt  is made to
         deal  with block  structure; if  you have  two Pascal
         procedures  with  the  same  name  but  in  different
         blocks, ctags may yield inadequate results.

     2.  The ctags command does not know about #ifdef.

FLAGS

     -a  Appends to tags file.
     -w  Suppresses warning diagnostics.
     -x  Causes ctags to  display a list of  object names, the
         line number and  file name on which  each is defined,
         as well  as the text  of that line.  This  provides a
         simple index index.  If  you specify this flag, ctags
         does not build a tags file.
     -u  Updates  the specified  files in  tags; that  is, all
         references to  them are  deleted, and the  new values
         are appended  to the  file.  This  flag may  be slow.
         (It  is usually  faster  to simply  rebuild the  tags
         file.)

FILES

     tags      Output tags file.

RELATED INFORMATION

     The following commands:   "ex" and "vi, vedit, view."