wget/lib/basename.c

65 lines
1.8 KiB
C

/* basename.c -- return the last element in a file name
Copyright (C) 1990, 1998-2001, 2003-2006, 2009-2023 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 3 of the License, 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, see <https://www.gnu.org/licenses/>. */
#include <config.h>
#include "dirname.h"
#include <string.h>
#include "xalloc.h"
char *
base_name (char const *name)
{
char const *base = last_component (name);
idx_t length;
int dotslash_len;
if (*base)
{
length = base_len (base);
/* Collapse a sequence of trailing slashes into one. */
length += ISSLASH (base[length]);
/* On systems with drive letters, "a/b:c" must return "./b:c" rather
than "b:c" to avoid confusion with a drive letter. On systems
with pure POSIX semantics, this is not an issue. */
dotslash_len = FILE_SYSTEM_PREFIX_LEN (base) != 0 ? 2 : 0;
}
else
{
/* There is no last component, so NAME is a file system root or
the empty string. */
base = name;
length = base_len (base);
dotslash_len = 0;
}
char *p = ximalloc (dotslash_len + length + 1);
if (dotslash_len)
{
p[0] = '.';
p[1] = '/';
}
/* Finally, copy the basename. */
memcpy (p + dotslash_len, base, length);
p[dotslash_len + length] = '\0';
return p;
}