.\" Copyright (c) 1987, 1990, 1993
.\" The Regents of the University of California. All rights reserved.
.\" %sccs.include.redist.roff%
.\" @(#)ctags.1 8.1 (Berkeley) %G%
A tags file gives the locations of specified objects in a group of files.
Each line of the tags file contains the object name, the file in which it
is defined, and a search pattern for the object definition, separated by
can quickly locate these object definitions.
Depending upon the options provided to
objects will consist of subroutines, typedefs, defines, structs,
use backward searching patterns
use forward searching patterns
that don't take arguments;
that take arguments are tagged automatically.
Places the tag descriptions in a file called
The default behaviour is to place them in a file called
create tags for typedefs, structs, unions, and enums.
update the specified files in the
references to them are deleted, and the new values are appended to the
file. (Beware: this option is implemented in a way which is rather
slow; it is usually faster to simply rebuild the
An index of the form expected by
is produced on the standard output. This listing
contains the object name, file name, and page number (assuming 64
line pages). Since the output will be sorted into lexicographic order,
it may be desired to run the output through
.Bd -literal -offset indent
ctags \-v files \&| sort \-f > index
suppress warning diagnostics.
produces 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
source files and are searched for C style routine and macro definitions.
are assumed to be lisp files if their
first non-blank character is `;', `(', or `[',
treated as lex files. Other files are first examined to see if they
contain any Pascal or Fortran routine definitions, and, if not, are
searched for C style definitions.
is treated specially in C programs. The tag formed
to the name of the file, with the
and any leading pathname components removed. This
practical in directories with more than one
Yacc and lex files each have a special tag.
of the second section of the yacc file, and
the second section of the lex file.
.Bl -tag -width tags -compact
exits with a value of 1 if an error occurred, 0 otherwise.
Duplicate objects are not considered errors.
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.
understand about Pascal types.
The method of deciding whether to look for C, Pascal or
relies on the input being well formed, and any syntactical
errors will completely confuse it. It also finds some legal syntax
confusing; for example, since it doesn't understand
(incidentally, that's a feature, not a bug), any code with unbalanced
will cause it to become somewhat disoriented.
In a similar fashion, multiple line changes within a definition will
cause it to enter the last line of the object, rather than the first, as
the searching pattern. The last line of multiple line