-/* This will return 1, with the first character in buf being the
- * character following the next instance of c in the file. This will
- * read the file as needed. If there's an error, -errno is returned;
- * if the end of the file is reached, 0 is returned.
- */
-static int next(int fd, char *buf, int size, char c)
-{
- int n, len;
- char *ptr;
-
- while((ptr = strchr(buf, c)) == NULL){
- n = read(fd, buf, size - 1);
- if(n == 0)
- return 0;
- else if(n < 0)
- return -errno;
-
- buf[n] = '\0';
- }
-
- ptr++;
- len = strlen(ptr);
- memmove(buf, ptr, len + 1);
-
- /* Refill the buffer so that if there's a partial string that we care
- * about, it will be completed, and we can recognize it.
- */
- n = read(fd, &buf[len], size - len - 1);
- if(n < 0)
- return -errno;
-
- buf[len + n] = '\0';
- return 1;
-}
-
-static int checked_tmpdir = 0;
-
-/* Look for a tmpfs mounted at /dev/shm. I couldn't find a cleaner
- * way to do this than to parse /proc/mounts. statfs will return the
- * same filesystem magic number and fs id for both /dev and /dev/shm
- * when they are both tmpfs, so you can't tell if they are different
- * filesystems. Also, there seems to be no other way of finding the
- * mount point of a filesystem from within it.
- *
- * If a /dev/shm tmpfs entry is found, then we switch to using it.
- * Otherwise, we stay with the default /tmp.
- */
-static void which_tmpdir(void)
-{
- int fd, found;
- char buf[128] = { '\0' };
-
- if(checked_tmpdir)
- return;
-
- checked_tmpdir = 1;
-
- printf("Checking for tmpfs mount on /dev/shm...");
-
- fd = open("/proc/mounts", O_RDONLY);
- if(fd < 0){
- printf("failed to open /proc/mounts, errno = %d\n", errno);
- return;
- }
-
- while(1){
- found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), ' ');
- if(found != 1)
- break;
-
- if(!strncmp(buf, "/dev/shm", strlen("/dev/shm")))
- goto found;
-
- found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), '\n');
- if(found != 1)
- break;
- }
-
-err:
- if(found == 0)
- printf("nothing mounted on /dev/shm\n");
- else if(found < 0)
- printf("read returned errno %d\n", -found);
-
- return;
-
-found:
- found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), ' ');
- if(found != 1)
- goto err;
-
- if(strncmp(buf, "tmpfs", strlen("tmpfs"))){
- printf("not tmpfs\n");
- return;
- }
-
- printf("OK\n");
- default_tmpdir = "/dev/shm";
-}
-