basename

DIRNAME(3)		  Linux Programmer’s Manual		   DIRNAME(3)



NAME
       dirname, basename - Parse pathname components

SYNOPSIS
       #include <libgen.h>

       char *dirname(char *path);
       char *basename(char *path);

DESCRIPTION
       Warning: there are two different functions basename - see below.

       The  functions  dirname	and basename break a null-terminated pathname
       string into directory and filename components.	In  the	 usual	case,
       dirname	returns	 the  string up to, but not including, the final ’/’,
       and basename returns the component following the final ’/’.   Trailing
       ’/’ characters are not counted as part of the pathname.

       If path does not contain a slash, dirname returns the string "." while
       basename returns a copy of path.	 If path is the string "/", then both
       dirname and basename return the string "/".  If path is a NULL pointer
       or points to an empty string, then both dirname	and  basename  return
       the string ".".

       Concatenating  the  string  returned by dirname, a "/", and the string
       returned by basename yields a complete pathname.

       Both dirname and basename may modify the contents of path,  so  copies
       should  be  passed to these functions.  Furthermore, dirname and base-
       name may return pointers to statically allocated memory which  may  be
       overwritten by subsequent calls.

       The  following  list  of examples (taken from SUSv2) shows the strings
       returned by dirname and basename for different paths:

       path	      dirname	     basename
       "/usr/lib"     "/usr"	     "lib"
       "/usr/"	      "/"	     "usr"
       "usr"	      "."	     "usr"
       "/"	      "/"	     "/"
       "."	      "."	     "."
       ".."	      "."	     ".."

EXAMPLE
	      char *dirc, *basec, *bname, *dname;
	      char *path = "/etc/passwd";

	      dirc = strdup(path);
	      basec = strdup(path);
	      dname = dirname(dirc);
	      bname = basename(basec);
	      printf("dirname=%s, basename=%s\n", dname, bname);

RETURN VALUE
       Both dirname and basename return pointers to null-terminated  strings.

NOTES
       There  are  two	different  versions  of	 basename - the POSIX version
       described above, and the GNU version one gets after
	 #define _GNU_SOURCE
	 #include <string.h>
       The GNU version never modifies its argument,  and  returns  the	empty
       string  when path has a trailing slash, and in particular also when it
       is "/".	There is no GNU version of dirname.

       With glibc, one gets the POSIX version of basename when <libgen.h>  is
       included, and the GNU version otherwise.

BUGS
       In  the	glibc implementation of the POSIX versions of these functions
       they modify their argument, and segfault when  called  with  a  static
       string like "/usr/".  Before glibc 2.2.1, the glibc version of dirname
       did not correctly handle pathnames with trailing ’/’  characters,  and
       generated a segfault if given a NULL argument.

CONFORMING TO
       POSIX 1003.1-2001

SEE ALSO
       dirname(1), basename(1),



GNU				  2000-12-14			   DIRNAME(3)