/*
* resolve /proc/$pid/cwd
*/
int
proc_cwd(pid_t pid, char **buf)
{
int ret;
char *cwd, *linkcwd;
struct stat s;
assert(pid >= 1);
assert(buf);
if (asprintf(&linkcwd, "/proc/%lu/cwd", (unsigned long)pid) < 0)
return -ENOMEM;
ret = readlink_alloc(linkcwd, &cwd);
free(linkcwd);
if (ret)
return ret;
/* If the current working directory of a process is removed after the
* process started, /proc/$pid/cwd is a dangling symbolic link and
* points to "/path/to/current/working/directory (deleted)".
*/
if (stat(cwd, &s) && errno == ENOENT) {
char *c;
if ((c = strrchr(cwd, ' ')))
cwd[c - cwd] = '\0';
}
*buf = cwd;
return 0;
}
static char *readlink_slash_alloc(char *path) {
char *p, *q, c;
for (p = path + strlen(path); p != path && p[-1] == '/'; --p) {}
if (p == path) return NULL;
for (q = p; q != path && q[-1] == '/'; --q) {}
for (; q != path && q[-1] != '/'; --q) {}
/* Don't follow symlink if ends with /.. or /. */
if (q[0] == '.' && (q[1] == '/' || q[1] == '\0' ||
(q[1] == '.' && (q[2] == '/' || q[2] == '\0')))) return NULL;
c = *p;
*p = '\0';
q = readlink_alloc(path);
*p = c;
return q;
}
/* Resolve symlinks until a non-symlink is found. */
static char *readlink_alloc_all(const char *path) {
char *path2, *path1 = strdup(path);
while ((path2 = readlink_alloc(path1))) {
if (path2[0] != '/') {
char *p;
for (p = path1 + strlen(path1); p != path1 && p[-1] != '/'; --p) {}
if (p != path1) {
*p = '\0'; /* Remove basename from path1. */
p = combine_paths_dotdot_alloc(path1, path2);
free(path2);
path2 = p;
}
}
free(path1);
path1 = path2;
}
return path1;
}
/*
* resolve /proc/$pid/fd/$dirfd
*/
int
proc_fd(pid_t pid, int dfd, char **buf)
{
int ret;
char *fd, *linkdir;
assert(pid >= 1);
assert(dfd >= 0);
assert(buf);
if (asprintf(&linkdir, "/proc/%lu/fd/%d", (unsigned long)pid, dfd) < 0)
return -ENOMEM;
ret = readlink_alloc(linkdir, &fd);
free(linkdir);
if (!ret)
*buf = fd;
return ret;
}
static char *get_up_dir_alloc(const char *dir) {
char *dirup = NULL, *p;
if (0 == strcmp(dir, "..") || (dirup = readlink_alloc(dir))) {
free(dirup);
return strdupcat(dir, "/..", "");
}
dirup = strdupcat(dir, ".", "");
for (p = dirup + strlen(dirup) - 1; p != dirup && p[-1] != '/'; --p) {}
if (p == dirup) {
*p++ = '.';
if (0 == strcmp(dir, ".")) *p++ = '.';
*p = '\0';
} else if (dirup[0] == '/' && dirup[1] == '\0') {
fdprint(2, strdupcat("xstatic: error: no parent dir for: ", dir, "\n"));
exit(122);
} else {
p[-1] = '\0'; /* Remove basename of dirup. */
}
return dirup;
}
