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/* Test suite for GNU tar - SEEK_HOLE detector.
Copyright 2015-2016 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, 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 <http://www.gnu.org/licenses/>.
Description: detect whether it is possible to work with SEEK_HOLE on
particular operating system and file system. */
#include "config.h"
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
enum {
EX_OK = 0, /* SEEK_HOLE support */
EX_FAIL, /* test failed - no SEEK_HOLE support */
EX_BAD, /* test is not relevant */
};
int
check_seek_hole (int fd)
{
#ifdef SEEK_HOLE
struct stat stat;
off_t offset;
/* hole of 100MB */
if (lseek (fd, 100*1024*1024, SEEK_END) < 0)
return EX_BAD;
/* piece of data */
if (write (fd, "data\n", 5) != 5)
return EX_BAD;
/* another hole */
if (lseek (fd, 100*1024*1024, SEEK_END) < 0)
return EX_BAD;
/* piece of data */
if (write (fd, "data\n", 5) != 5)
return EX_BAD;
if (fstat (fd, &stat))
return EX_BAD;
offset = lseek (fd, 0, SEEK_DATA);
if (offset == (off_t)-1)
return EX_FAIL;
offset = lseek (fd, offset, SEEK_HOLE);
if (offset == (off_t)-1 || offset == stat.st_size)
return EX_FAIL;
return EX_OK;
#else
return EX_BAD;
#endif
}
int
main ()
{
#ifdef SEEK_HOLE
int rc;
char template[] = "testseekhole-XXXXXX";
int fd = mkstemp (template);
if (fd == -1)
return EX_BAD;
rc = check_seek_hole (fd);
close (fd);
unlink (template);
return rc;
#else
return EX_FAIL;
#endif
}
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