ctags(1)
NAME
ctags − create a tags file
SYNTAX
ctags [ −BFatuwvx ] name...
DESCRIPTION
The ctags command makes a tags file for the ex(1) editor from the specified C, Pascal and Fortran 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 blanks or tabs. Using the tags file, ex can quickly find these object name definitions.
If the −x flag is given, 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.
If the −v flag is given, an index is produced on the standard output. This listing contains 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. For example,
ctags −v files | sort −f > index
Files whose name ends in .c or .h are assumed to be C source files and are searched for C routine and macro definitions. 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.
OPTIONS
−B Use backward searching patterns (?...?).
−F Use forward searching patterns (/.../) (default).
−a Append to tags file.
−t Create tags for typedefs.
−u Causing the specified files to be updated in tags, that is, all references to them are deleted, and the new values are appended to the file. Note: This option is implemented in a rather slow way and it is usually faster to simply rebuild the tags file.
−w Suppressing warning diagnostics.
The tag main is treated specially in C programs. The tag formed is created by prepending M to the name of the file, with a trailing .c removed, if any, and leading pathname components also removed. This makes use of ctags practical in directories with more than one program.
RESTRICTIONS
No attempt is made to deal with block structure. Two Pascal procedures in different blocks with the same name does not work.
The method of deciding whether to look for C or Pascal and FORTRAN functions is a hack.
The ctags command does not know about #ifdefs.
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.
FILES
tagsoutput tags file