lib/libc/gen/basename.c

   1 /*
   2  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  17  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  18  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  19  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  *
  27  * $OpenBSD: basename.c,v 1.4 1999/05/30 17:10:30 espie Exp $
  28  * $FreeBSD: src/lib/libc/gen/basename.c,v 1.6 2002/12/21 07:12:35 bbraun Exp $
  29  * $DragonFly: src/lib/libc/gen/basename.c,v 1.8 2005/09/18 16:09:45 asmodai Exp $
  30  */
  31
  32 #include <errno.h>
  33 #include <libgen.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <sys/param.h>
  37
  38 char *
  39 basename(const char *path)
  40 {
  41         static char *bname = NULL;
  42         const char *endp, *startp;
  43
  44         if (bname == NULL) {
  45                 bname = (char *)malloc(MAXPATHLEN);
  46                 if (bname == NULL)
  47                         return(NULL);
  48         }
  49
  50         /* Empty or NULL string gets treated as "." */
  51         if (path == NULL || *path == '\0') {
  52                 strlcpy(bname, ".", MAXPATHLEN);
  53                 return(bname);
  54         }
  55
  56         /* Strip trailing slashes */
  57         endp = path + strlen(path) - 1;
  58         while (endp > path && *endp == '/')
  59                 endp--;
  60
  61         /* All slashes becomes "/" */
  62         if (endp == path && *endp == '/') {
  63                 strlcpy(bname, "/", MAXPATHLEN);
  64                 return(bname);
  65         }
  66
  67         /* Find the start of the base */
  68         startp = endp;
  69         while (startp > path && *(startp - 1) != '/')
  70                 startp--;
  71
  72         if (strlcpy(bname, startp, (endp - startp) + 2) >= MAXPATHLEN) {
  73                 errno = ENAMETOOLONG;
  74                 return(NULL);
  75         }
  76         return(bname);
  77 }