coreutils/lib/dirname.c

81 lines
2.1 KiB
C

/* dirname.c -- return all but the last element in a path
Copyright (C) 1990, 1998 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef STDC_HEADERS
# include <stdlib.h>
#else
char *malloc ();
#endif
#if defined STDC_HEADERS || defined HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
# ifndef strrchr
# define strrchr rindex
# endif
#endif
#include "dirname.h"
/* Return the leading directories part of PATH,
allocated with malloc. If out of memory, return 0.
Assumes that trailing slashes have already been
removed. */
char *
dir_name (const char *path)
{
char *newpath;
char *slash;
int length; /* Length of result, not including NUL. */
slash = strrchr (path, '/');
if (slash == 0)
{
/* File is in the current directory. */
path = ".";
length = 1;
}
else
{
/* Remove any trailing slashes from the result. */
#ifdef MSDOS
char *lim = (path[0] >= 'A' && path[0] <= 'z' && path[1] == ':')
? path + 2 : path;
/* If canonicalized "d:/path", leave alone the root case "d:/". */
while (slash > lim && *slash == '/')
--slash;
#else
while (slash > path && *slash == '/')
--slash;
#endif
length = slash - path + 1;
}
newpath = (char *) malloc (length + 1);
if (newpath == 0)
return 0;
strncpy (newpath, path, length);
newpath[length] = 0;
return newpath;
}