wait-time-sync: add optional -t/--timeout parameter

packages/sysutils/wait-time-sync/sources/wait-time-sync.c

@@ -2,14 +2,43 @@
 /* Copyright (C) 2020-present Team LibreELEC (https://libreelec.tv) */
 
 #include <sys/timex.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
+#include <string.h>
 #include <errno.h>
+#include <limits.h>
 
-int main()
+void usage(char *name)
 {
-  int rc;
+  if (!name)
+    name = "wait-time-sync";
 
-  for (;;)
+  printf("Usage: %s [-t seconds | --timeout seconds]\n", name);
+  exit(2);
+}
+
+int main(int argc, char** argv)
+{
+  unsigned timeout = UINT_MAX;
+  int rc = 0;
+
+  if (argc == 3)
+  {
+    unsigned long val;
+    char *p;
+
+    if (strcmp(argv[1], "-t") && strcmp(argv[1], "--timeout"))
+      usage(argv[0]);
+    val = strtoul(argv[2], &p, 0);
+    if (*p || val == 0 || val >= UINT_MAX/3)
+      usage(argv[0]);
+    timeout = (unsigned)val * 3;
+  }
+  else if (argc != 1)
+    usage(argv[0]);
+
+  for ( ; timeout; --timeout)
   {
     struct timex tx = {};
 
@@ -19,5 +48,5 @@ int main()
     usleep(1000000U/3);
   }
 
-  return rc == -1 ? errno : 0;
+  return rc == -1 ? errno : !timeout;
 }