git/t/helper/test-truncate.c
brian m. carlson 678eb55f5d t: add a test helper to truncate files
In a future commit, we're going to work with some large files which will
be at least 4 GiB in size.  To take advantage of the sparseness
functionality on most Unix systems and avoid running the system out of
disk, it would be convenient to use truncate(2) to simply create a
sparse file of sufficient size.

However, the GNU truncate(1) utility isn't portable, so let's write a
tiny test helper that does the work for us.

Signed-off-by: brian m. carlson <bk2204@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-13 13:33:35 -07:00

26 lines
456 B
C

#include "test-tool.h"
#include "git-compat-util.h"
/*
* Truncate a file to the given size.
*/
int cmd__truncate(int argc, const char **argv)
{
char *p = NULL;
uintmax_t sz = 0;
int fd = -1;
if (argc != 3)
die("expected filename and size");
sz = strtoumax(argv[2], &p, 0);
if (*p)
die("invalid size");
fd = xopen(argv[1], O_WRONLY | O_CREAT, 0600);
if (ftruncate(fd, (off_t) sz) < 0)
die_errno("failed to truncate file");
return 0;
}