cgls: don't show kernel threads by default

[elogind.git] / src / util.c

diff --git a/src/util.c b/src/util.c
index de5feeb8d03eb4a2db31f929d167a5b99c29a63b..ef6eea4b9f591321a430a67920c4673251945b3d 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -1100,6 +1100,37 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char *
         return 0;
 }
 
+int is_kernel_thread(pid_t pid) {
+        char *p;
+        size_t count;
+        char c;
+        bool eof;
+        FILE *f;
+
+        if (pid == 0)
+                return 0;
+
+        if (asprintf(&p, "/proc/%lu/cmdline", (unsigned long) pid) < 0)
+                return -ENOMEM;
+
+        f = fopen(p, "re");
+        free(p);
+
+        if (!f)
+                return -errno;
+
+        count = fread(&c, 1, 1, f);
+        eof = feof(f);
+        fclose(f);
+
+        /* Kernel threads have an empty cmdline */
+
+        if (count <= 0)
+                return eof ? 1 : -errno;
+
+        return 0;
+}
+
 int get_process_exe(pid_t pid, char **name) {
         int r;