NAME
ctags
- create a tags file
SYNOPSIS
ctags
[-BFadtuwvx]
[-f tagsfile]
name ...
DESCRIPTION
ctags
makes a tags file for
ex(1)
from the specified C,
Pascal, Fortran,
YACC,
lex, and lisp sources.
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
white-space.
Using the
tags
file,
ex(1)
can quickly locate these object definitions.
Depending upon the options provided to
,
objects will consist of subroutines, typedefs, defines, structs,
enums and unions.
- -B
-
use backward searching patterns
(
?...?
).
- -F
-
use forward searching patterns
(
/.../
)
(the default).
- -a
-
append to
tags
file.
- -d
-
create tags for
#defines
that don't take arguments;
#defines
that take arguments are tagged automatically.
- -f
-
Places the tag descriptions in a file called
tagsfile.
The default behaviour is to place them in a file called
tags.
- -t
-
create tags for typedefs, structs, unions, and enums.
- -u
-
update the specified files in the
tags
file, that is, all
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
tags
file.)
- -v
-
An index of the form expected by
vgrind(1)
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
sort(1).
Sample use:
-
ctags -v files | sort -f > index
vgrind -x index
- -w
-
suppress warning diagnostics.
- -x
-
ctags
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
function index.
Files whose names end in
`.c'
or
`.h'
are assumed to be C
source files and are searched for C style routine and macro definitions.
Files whose names end in
`.y'
are assumed to be
YACC
source files.
Files whose names end in
`.l'
are assumed to be lisp files if their
first non-blank character is
`;',
`(',
or
`[',
otherwise, they are
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.
The tag
main
is treated specially in C programs.
The tag formed
is created by prepending
M
to the name of the file, with the
trailing
`.c'
and any leading pathname components removed.
This
makes use of
ctags
practical in directories with more than one
program.
Yacc and lex files each have a special tag.
Yyparse
is the start
of the second section of the yacc file, and
yylex
is the start of
the second section of the lex file.
EXIT STATUS
ctags
exits with a value of 1 if an error occurred, 0 otherwise.
Duplicate objects are not considered errors.
FILES
tags
-
default output tags file
SEE ALSO
ex(1),
vi(1)
HISTORY
The
ctags
command appeared in
3.0BSD.
BUGS
Recognition of
functions,
subroutines
and
procedures
for
FORTRAN
and Pascal is done in 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.
ctags
doesn't
understand about Pascal types.
The method of deciding whether to look for C, Pascal or
FORTRAN
functions is a hack.
ctags
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
#ifdef
's
(incidentally, that's a feature, not a bug), any code with unbalanced
braces inside
#ifdef
's
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
typedef
's
will similarly be noted.