glibc/stdlib/xpg_basename.c

71 lines
1.9 KiB
C

/* Return basename of given pathname according to the weird XPG specification.
Copyright (C) 1997-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <string.h>
#include <libgen.h>
char *
__xpg_basename (char *filename)
{
char *p;
if (filename == NULL || filename[0] == '\0')
/* We return a pointer to a static string containing ".". */
p = (char *) ".";
else
{
p = strrchr (filename, '/');
if (p == NULL)
/* There is no slash in the filename. Return the whole string. */
p = filename;
else
{
if (p[1] == '\0')
{
/* We must remove trailing '/'. */
while (p > filename && p[-1] == '/')
--p;
/* Now we can be in two situations:
a) the string only contains '/' characters, so we return
'/'
b) p points past the last component, but we have to remove
the trailing slash. */
if (p > filename)
{
*p-- = '\0';
while (p > filename && p[-1] != '/')
--p;
}
else
/* The last slash we already found is the right position
to return. */
while (p[1] != '\0')
++p;
}
else
/* Go to the first character of the name. */
++p;
}
}
return p;
}