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Name

ctags - create a tags file for use with ex and vi

Synopsis

/usr/bin/ctags [ -aBFtuvwx ] [ -f tagsfile ] file...

/usr/xpg4/bin/ctags [ -aBFuvwx ] [ -f tagsfile ] file...

Availability

/usr/bin/ctags

SUNWtoo

/usr/xpg4/bin/ctags

SUNWxcu4

Description

ctags makes a tags file for ex(1) from the specified C, C++, Pascal, FORTRAN, yacc(1) , and lex(1) 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 either C or C++ source files and are searched for C/C++ routine and macro definitions. Files with names ending in .cc, .C, or .cxx, are assumed to be C++ source files. 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 or C++ programs. The tag formed is created by prepending M to file, with a trailing .c , .cc .C, or .cxx removed, if any, and leading path name components also removed. This makes use of ctags practical in directories with more than one program.

Options

The precedence of the options that pertain to printing is -x, -v, then the remaining options. The following options are supported:
-a
Append output to an existing tags file.
-B
Use backward searching patterns (?...?).
-f tagsfile
Places the tag descriptions in a file called tagsfile instead of tags.
-F
Use forward searching patterns (/.../) (default).
-t
Create tags for typedefs. /usr/xpg4/bin/ctags creates tags for typedefs by default.
-u
Update the specified files in tags, 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
Produce on the standard output an index listing the function 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 -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.

Operands

The following file operands are supported:
file.c
Files with basenames ending with the .c suffix are treated as C-language source code.
file.h
Files with basenames ending with the .h suffix are treated as C-language source code.
file.f
Files with basenames ending with the .f suffix are treated as FORTRAN-language source code.

Usage

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

Examples

Using ctags with the -v option produces entries in an order which may not always be appropriate for vgrind. To produce results in alphabetical order, you may want to run the output through ‘sort -f’. 


example% ctags -v filename.c filename.h | sort -f > index
example% vgrind -x index

To build a tags file for C sources in a directory hierarchy rooted at sourcedir, first create an empty tags file, and then run find(1) : 


example% cd sourcedir  ; rm -f tags ; touch tags
example% find . \( -name SCCS -prune -name \\
 ’*.c’ -o -name ’*.h’ \) -exec ctags -u {} \;

Note that spaces must be entered exactly as shown.

Environment

See environ(5) for descriptions of the following environment variables that affect the execution of ctags: LC_COLLATE , LC_CTYPE , LC_MESSAGES , and NLSPATH .

Exit Status

The following exit values are returned:
  1. Successful completion.
    >0
    An error occurred.

    Files

    tags
    output tags file

    See Also

    ex(1) , lex(1) , vgrind(1) , vi(1) , yacc(1) , environ(5)

    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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