+ return -1;
+}
+
+/* Check program exists and is executable on $PATH. Actually, we
+ * just assume PATH contains the default entries (see main() above).
+ */
+int
+prog_exists (const char *prog)
+{
+ static const char * const dirs[] =
+ { "/sbin", "/usr/sbin", "/bin", "/usr/bin" };
+ size_t i;
+ char buf[1024];
+
+ for (i = 0; i < sizeof dirs / sizeof dirs[0]; ++i) {
+ snprintf (buf, sizeof buf, "%s/%s", dirs[i], prog);
+ if (access (buf, X_OK) == 0)
+ return 1;
+ }
+ return 0;