glibc/dirent/scandir-tail.c

110 lines
2.8 KiB
C

/* Logic guts of scandir*.
Copyright (C) 1992-2017 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
<http://www.gnu.org/licenses/>. */
#include <dirent.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <libc-lock.h>
#ifndef SCANDIR_TAIL
# define SCANDIR_TAIL __scandir_tail
# define READDIR __readdir
# define DIRENT_TYPE struct dirent
#endif
int
SCANDIR_TAIL (DIR *dp,
DIRENT_TYPE ***namelist,
int (*select) (const DIRENT_TYPE *),
int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **))
{
if (dp == NULL)
return -1;
int save = errno;
__set_errno (0);
int result;
struct scandir_cancel_struct c = { .dp = dp };
__libc_cleanup_push (&__scandir_cancel_handler, &c);
DIRENT_TYPE **v = NULL;
size_t vsize = 0;
DIRENT_TYPE *d;
while ((d = READDIR (dp)) != NULL)
{
if (select != NULL)
{
int selected = (*select) (d);
/* The SELECT function might have changed errno. It was
zero before and it need to be again to make the later
tests work. */
__set_errno (0);
if (!selected)
continue;
}
else
__set_errno (0);
if (__glibc_unlikely (c.cnt == vsize))
{
if (vsize == 0)
vsize = 10;
else
vsize *= 2;
DIRENT_TYPE **new = realloc (v, vsize * sizeof *v);
if (new == NULL)
break;
c.v = v = new;
}
size_t dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
DIRENT_TYPE *vnew = malloc (dsize);
if (vnew == NULL)
break;
v[c.cnt++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize);
}
if (__glibc_likely (errno == 0))
{
__closedir (dp);
/* Sort the list if we have a comparison function to sort with. */
if (cmp != NULL)
qsort (v, c.cnt, sizeof *v, (__compar_fn_t) cmp);
*namelist = v;
result = c.cnt;
}
else
{
/* This frees everything and calls closedir. */
__scandir_cancel_handler (&c);
result = -1;
}
__libc_cleanup_pop (0);
if (result >= 0)
__set_errno (save);
return result;
}