blob: 082c71e601e451cf77ef022555d25d102f054de2 (
plain)
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
60
61
|
#include "config.h"
#include <stdio.h>
#include <string.h>
/**
* noerr - routines for cleaning up without blatting errno
*
* It is a good idea to follow the standard C convention of setting errno in
* your own helper functions. Unfortunately, care must be taken in the error
* paths as most standard functions can (and do) overwrite errno, even if they
* succeed.
*
* Example:
* #include <sys/types.h>
* #include <sys/stat.h>
* #include <fcntl.h>
* #include <stdbool.h>
* #include <string.h>
* #include <errno.h>
* #include <ccan/noerr/noerr.h>
*
* static bool write_string_to_file(const char *file, const char *string)
* {
* int ret, fd = open(file, O_WRONLY|O_CREAT|O_EXCL, 0600);
* if (fd < 0)
* return false;
* ret = write(fd, string, strlen(string));
* if (ret < 0) {
* // Preserve errno from write above.
* close_noerr(fd);
* unlink_noerr(file);
* return false;
* }
* if (close(fd) != 0) {
* // Again, preserve errno.
* unlink_noerr(file);
* return false;
* }
* // A short write means out of space.
* if (ret < strlen(string)) {
* unlink(file);
* errno = ENOSPC;
* return false;
* }
* return true;
* }
*
* License: CC0 (Public domain)
* Author: Rusty Russell <rusty@rustcorp.com.au>
*/
int main(int argc, char *argv[])
{
if (argc != 2)
return 1;
if (strcmp(argv[1], "depends") == 0)
/* Nothing. */
return 0;
return 1;
}
|