1/* Test whether /proc/{self,$PID}/path/a.out is correctly simulated. */
2
3#include <limits.h>
4#include <stdio.h>
5#include <strings.h>
6#include <unistd.h>
7#include <sys/fcntl.h>
8
9static void test_readlink(const char *cwd, const char *label,
10      const char *path)
11{
12   char buf[PATH_MAX];
13   int n;
14
15   if ((n = readlink(path, buf, sizeof(buf) - 1)) >= 0) {
16      const char *p;
17      size_t len = strlen(cwd);
18
19      buf[n] = '\0';
20
21      p = buf;
22      if (!strncmp(buf, cwd, len))
23         p += len;
24      printf("Result of readlink(\"%s\"): %s\n", label, p);
25   }
26   else
27      perror("readlink");
28}
29
30static void test_readlinkat(const char *cwd, const char *label,
31      const char *path)
32{
33   char buf[PATH_MAX];
34   int n;
35
36   if ((n = readlinkat(AT_FDCWD, path, buf, sizeof(buf) - 1)) >= 0) {
37      const char *p;
38      size_t len = strlen(cwd);
39
40      buf[n] = '\0';
41
42      p = buf;
43      if (!strncmp(buf, cwd, len))
44         p += len;
45      printf("Result of readlinkat(\"%s\"): %s\n", label, p);
46   }
47   else
48      perror("readlinkat");
49}
50
51int main(void)
52{
53   char cwd[PATH_MAX];
54   char path[PATH_MAX];
55
56   cwd[0] = '\0';
57   if (!getcwd(cwd, sizeof(cwd) - 1)) /* '-1' to make room for '/' */
58      perror("getcwd");
59   strcat(cwd, "/");
60
61   snprintf(path, sizeof(path), "/proc/%ld/path/a.out", (long)getpid());
62
63   test_readlink(cwd, "/proc/self/path/a.out", "/proc/self/path/a.out");
64   test_readlink(cwd, "/proc/<pid>/path/a.out", path);
65
66   test_readlinkat(cwd, "/proc/self/path/a.out", "/proc/self/path/a.out");
67   test_readlinkat(cwd, "/proc/<pid>/path/a.out", path);
68
69   return 0;
70}
71
72