lib: (pidutils) improve the return protocol

Instead of using generic return codes, lets
be more precise and return negative errno
numbers and set errno accordingly, so that
higher level callers can report errors more
accurately.

Signed-off-by: Christian Goeschel Ndjomouo <cgoesc2@wgu.edu>

diff --git a/lib/pidutils.c b/lib/pidutils.c
index 245cbb452feec02934f173bb2db75128a3fbd9fd..e1a474d96028dce7a5f644e25e5a1370d5f27410 100644 (file)
--- a/lib/pidutils.c
+++ b/lib/pidutils.c
@@ -22,7 +22,8 @@
  * If @pfd_ino is not destined to be set, pass it as NULL.
  *
  * Return: On success, 0 is returned.
- *         On failure, -1 is returned and errno is set to indicate the issue.
+ *         On failure, a negative errno number is returned
+ *         and errno is set to indicate the issue.
  */
 int ul_parse_pid_str(char *pidstr, pid_t *pid_num, uint64_t *pfd_ino)
 {
@@ -30,37 +31,30 @@ int ul_parse_pid_str(char *pidstr, pid_t *pid_num, uint64_t *pfd_ino)
        char *end = NULL;
        int64_t num = 0;
 
-       if (!pidstr || !*pidstr || !pid_num) {
-               errno = EINVAL;
-               return -1;
-       }
+       if (!pidstr || !*pidstr || !pid_num)
+               return -(errno = EINVAL);
 
        num = strtoimax(pidstr, &end, 10);
-       if (num == 0 && end == pidstr) {
-               errno = EINVAL;
-               return -1;
-       }
+       if (num == 0 && end == pidstr)
+               return -(errno = EINVAL);
 
-       if (errno == ERANGE || (num <= 0 || num > SINT_MAX(pid_t))) {
-               errno = ERANGE;
-               return -1;
-       }
+       if (errno == ERANGE || (num <= 0 || num > SINT_MAX(pid_t)))
+               return -(errno = ERANGE);
 
        *pid_num = (pid_t) num;
 
        if (*end == ':' && pfd_ino) {
                rc = ul_strtou64(++end, pfd_ino, 10);
-               if (rc != 0 || *pfd_ino == 0) {
-                       errno = EINVAL;
-                       return -1;
-               }
+               if (rc < 0)
+                       return rc;
+
+               if (*pfd_ino == 0)
+                       return -(errno = ERANGE);
                *end = '\0';
        }
 
-       if (end && *end != '\0') {
-               errno = EINVAL;
-               return -1;
-       }
+       if (end && *end != '\0')
+               return -(errno = EINVAL);
        return 0;
 }