add askfirst tool

diff --git a/askfirst.c b/askfirst.c
new file mode 100644 (file)
index 0000000..2f948f8
--- /dev/null
+++ b/askfirst.c
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+static int redirect_output(const char *dev)
+{
+       pid_t p = setsid();
+       int fd;
+
+       chdir("/dev");
+       fd = open(dev, O_RDWR);
+       chdir("/");
+
+       if (fd < 0)
+               return -1;
+
+       close(STDIN_FILENO);
+       close(STDOUT_FILENO);
+       close(STDERR_FILENO);
+
+       dup2(fd, STDIN_FILENO);
+       dup2(fd, STDOUT_FILENO);
+       dup2(fd, STDERR_FILENO);
+       tcsetpgrp(fd, p);
+       close(fd);
+
+       return 0;
+}
+
+int main(int argc, char **argv)
+{
+       if (redirect_output(argv[1]))
+               fprintf(stderr, "%s: Failed to open %s\n", argv[0], argv[1]);
+
+       printf("Please press Enter to activate this console.\n");
+       while (getchar() != 0xA)
+               ;
+       execvp(argv[2], &argv[2]);
+       printf("%s: Failed to execute %s\n", argv[0], argv[2]);
+
+       return -1;
+}