uclibc-ng/libc/string/dirname.c

/* dirname - return directory part of PATH.
   Copyright (C) 1996, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#define __USE_GNU
#include <libgen.h>
#include <string.h>


char * dirname(char *path)
{
    static const char dot[] = ".";
    char *last_slash;

    /* Find last '/'.  */
    last_slash = path != NULL ? strrchr (path, '/') : NULL;

    if (last_slash != NULL && last_slash != path && last_slash[1] == '\0')
	/* The '/' is the last character, we have to look further.  */
	last_slash = memrchr (path, '/', last_slash - path);

    if (last_slash != NULL)
    {
	/* Terminate the path.  */
	if (last_slash == path)
	    /* The last slash is the first character in the string.  We have to
	       return "/".  */
	    ++last_slash;

	last_slash[0] = '\0';
    }
    else
	/* This assignment is ill-designed but the XPG specs require to
	   return a string containing "." in any case no directory part is
	   found and so a static and constant string is required.  */
	path = (char *) dot;

    return path;
}