/*  $OpenBSD: dirname.c,v 1.4 1999/05/30 17:10:30 espie Exp $  */

/*
 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef lint
static char rcsid[] = "$OpenBSD: dirname.c,v 1.4 1999/05/30 17:10:30 espie Exp $";
const char* libtar_compat_dirname_getrcsid() { return rcsid; }
#endif /* not lint */

#include <errno.h>
#include <string.h>
#include <libtar/compat.h>
#include <libtarint/internal.h>

char *
openbsd_dirname(path)
  const char *path;
{
  static char bname[TAR_MAXPATHLEN];
  register const char *endp;

  /* Empty or NULL string gets treated as "." */
  if (path == NULL || *path == '\0') {
    (void)strcpy(bname, ".");
    return(bname);
  }

  /* Strip trailing slashes */
  endp = path + strlen(path) - 1;
  while (endp > path && *endp == '/')
    endp--;

  /* Find the start of the dir */
  while (endp > path && *endp != '/')
    endp--;

  /* Either the dir is "/" or there are no slashes */
  if (endp == path) {
    (void)strcpy(bname, *endp == '/' ? "/" : ".");
    return(bname);
  } else {
    do {
      endp--;
    } while (endp > path && *endp == '/');
  }

  if (endp - path + 1 > sizeof(bname)) {
    errno = ENAMETOOLONG;
    return(NULL);
  }
  (void)strncpy(bname, path, endp - path + 1);
  bname[endp - path + 1] = '\0';
  return(bname);
}