implement -o exit_after_connect

this is useful as a connectivity check

ftpfs.c

@@ -174,6 +174,7 @@ static struct fuse_opt ftpfs_opts[] = {
   FTPFS_OPT("codepage=%s",        codepage, 0),
   FTPFS_OPT("iocharset=%s",       iocharset, 0),
   FTPFS_OPT("nomulticonn",        multiconn, 0),
+  FTPFS_OPT("exit_after_connect", exit_after_connect, 1),
 
   FUSE_OPT_KEY("-h",             KEY_HELP),
   FUSE_OPT_KEY("--help",         KEY_HELP),
@@ -1502,6 +1503,7 @@ static void usage(const char* progname) {
 "    utf8                try to transfer file list with utf-8 encoding\n"
 "    codepage=STR        set the codepage the server uses\n"
 "    iocharset=STR       set the charset used by the client\n"
+"    exit_after_connect  after connecting to the FTP server, instead of passing control to FUSE, exit\n"
 "\n"
 "CurlFtpFS cache options:  \n"
 "    cache=yes|no              enable/disable cache (default: yes)\n"
@@ -1800,7 +1802,10 @@ int main(int argc, char** argv) {
   fuse_opt_insert_arg(&args, 1, tmp);
   g_free(tmp);
 
-  res = curlftpfs_fuse_main(&args);
+
+  if (!ftpfs.exit_after_connect) {
+    res = curlftpfs_fuse_main(&args);
+  }
 
   cancel_previous_multi();
   curl_multi_cleanup(ftpfs.multi);

ftpfs.h

@@ -67,6 +67,7 @@ struct ftpfs {
   char *codepage;
   char *iocharset;
   int multiconn;
+  int exit_after_connect;
 };
 
 extern struct ftpfs ftpfs;