1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define EXIT_BAD_OPTION 2
void usage(int fd, char * progname)
{
dprintf(fd, "Usage: %s [-o offset] -l length name\n", progname);
}
int try_fallocate(char * filename, int offset, int length)
{
int fd = open(filename, O_CREAT|O_WRONLY|O_TRUNC, 0644);
if (-1 == fd) return -1;
int res = posix_fallocate(fd, offset, length);
if (-1 == res) return -1;
res = close(fd);
if (-1 == res) return -1;
return 0;
}
int main(int argc, char * argv[])
{
int opt;
int offset = 0;
int length = 0;
char * filename;
while (-1 != (opt = getopt(argc, argv, "o:l:"))) {
switch (opt) {
case 'o':
offset = atoi(optarg);
break;
case 'l':
length = atoi(optarg);
break;
default:
usage(2, argv[0]);
exit(EXIT_BAD_OPTION);
}
}
if (0 >= length || argc <= optind) {
usage(2, argv[0]);
exit(EXIT_BAD_OPTION);
}
filename = argv[optind];
int res = try_fallocate(filename, offset, length);
if (-1 == res) {
dprintf(2, "%s: %s: %s\n", argv[0], filename, strerror(errno));
exit(EXIT_FAILURE);
}
}
|
