NAME
	  ctags	- Makes	a file of tags to help locate objects in
	  source files

     SYNOPSIS
	  ctags	[-aBdFtuvw] [-x	| -f tags_file]	file ...


	  The ctags command makes a tags file for ex and vi editors
	  from the specified C,	Pascal,	FORTRAN, yacc, lex, and	LISP
	  source files.	 A tags	file gives the locations of specified
	  objects (in this case	functions and type definitions)	in a
	  group	of files.

     FLAGS
	  -a  Appends to the tags file.

	  -f tags_file
	      Creates a	tags file with the name	specified by
	      tags_file.

	  -B  Uses backward searching pattern (?...?).

	  -d  Creates tags for #define directives that do not take
	      arguments.  #define directives that take arguments are
	      tagged automatically.

	  -F  Uses forward searching pattern (/.../) (default).

	  -t  Creates tags for type definitions	(typedef), and for
	      struct, union, and enum declarations.

	  -u  Updates the specified files in tags; that	is, all	refer-
	      ences 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.)

	  -v  Produces an index	of the form expected by	vgrind on the
	      standard output.	This listing contains the function
	      name, filename, and page number (assuming	64-line
	      pages).  Because the output will be sorted according to
	      the current collating sequence as	defined	by the value
	      of the LC_COLLATE	environment variable, it may be	desir-
	      able to run the output through sort -f.  Sample use:

	      ctags -v files | sort -f > index
	      vgrind -x	index



	  -w  Suppresses warning diagnostics.

	  -x  Causes ctags to display a	list of	object names, the line
	      number and filename on which each	is defined, as well as
	      the text of that line.  This provides a simple index,
	      which can	be printed out as an offline readable function
	      index.  If you specify this flag,	ctags does not build a
	      tags file, but writes to standard	output.


     DESCRIPTION
	  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 and type definitions with a line number.  Specifiers
	  are given in separate	fields on the line, separated by
	  spaces or tabs.  Using the tags file,	ex and vi can quickly
	  find these object definitions.

	  If a filename	ends in	.c or .h, it is	assumed	to be a	C
	  source file and is searched for C routine and	macro defini-
	  tions.  Files	whose names end	in .y are assumed to be	yacc
	  source files.	 Files whose names end in .l are assumed to be
	  either LISP files (if	their first nonspace character is ;
	  (semicolon), ( (open parenthesis), or	[ (open	bracket)) or
	  lex files otherwise.	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 filename, removing a
	  trailing .c (if any),	and removing the leading pathname com-
	  ponents.  This makes use of ctags practical in directories
	  with more than one program.

	Restrictions
	  Recognition of functions, subroutines, and procedures	for
	  FORTRAN and Pascal does not deal with	block structure.
	  Therefore, you cannot	have two Pascal	procedures in dif-
	  ferent blocks	with the same name.

	  The ctags command does not know about	ifdefs.

     FILES
	  tags	    Default tags file.	Use the	-f flag	to specify
		    another filename.


     RELATED INFORMATION
	  Commands:  ex(1), lex(1), vi(1)/vedit(1)/view(1), yacc(1).