gen/basename.c

   1 /*      $OpenBSD: basename.c,v 1.4 1999/05/30 17:10:30 espie Exp $      */
   2 /*      $FreeBSD: src/lib/libc/gen/basename.c,v 1.1.2.2 2001/07/23 10:13:04 dd Exp $    */
   3
   4 /*
   5  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  21  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  22  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  25  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  27  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  28  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #if defined(LIBC_RCS) && !defined(lint)
  32 static char rcsid[] = "$OpenBSD: basename.c,v 1.4 1999/05/30 17:10:30 espie Exp $";
  33 #endif /* not lint */
  34
  35 #include <errno.h>
  36 #include <libgen.h>
  37 #include <string.h>
  38 #include <sys/param.h>
  39 #include <stdlib.h>
  40
  41 char *
  42 basename(path)
  43         const char *path;
  44 {
  45         static char *bname = NULL;
  46         register const char *endp, *startp;
  47
  48         if( bname == NULL ) {
  49                 bname = malloc(MAXPATHLEN);
  50                 if( bname == NULL )
  51                         return NULL;
  52         }
  53
  54         /* Empty or NULL string gets treated as "." */
  55         if (path == NULL || *path == '\0') {
  56                 (void)strcpy(bname, ".");
  57                 return(bname);
  58         }
  59
  60         /* Strip trailing slashes */
  61         endp = path + strlen(path) - 1;
  62         while (endp > path && *endp == '/')
  63                 endp--;
  64
  65         /* All slashes becomes "/" */
  66         if (endp == path && *endp == '/') {
  67                 (void)strcpy(bname, "/");
  68                 return(bname);
  69         }
  70
  71         /* Find the start of the base */
  72         startp = endp;
  73         while (startp > path && *(startp - 1) != '/')
  74                 startp--;
  75
  76         if (endp - startp + 2 > MAXPATHLEN) {
  77                 errno = ENAMETOOLONG;
  78                 return(NULL);
  79         }
  80         (void)strncpy(bname, startp, endp - startp + 1);
  81         bname[endp - startp + 1] = '\0';
  82         return(bname);
  83 }