implement -o exit_after_connect

this is useful as a connectivity check

cache.c

@@ -385,6 +385,7 @@ static void cache_unity_fill(struct fuse_cache_operations *oper,
     cache_oper->listxattr   = oper->oper.listxattr;
     cache_oper->removexattr = oper->oper.removexattr;
     cache_oper->create      = oper->oper.create;
+    cache_oper->readdir     = oper->oper.readdir;
 }
 
 struct fuse_operations *cache_init(struct fuse_cache_operations *oper)
@@ -409,6 +410,7 @@ struct fuse_operations *cache_init(struct fuse_cache_operations *oper)
         cache_oper.utimens  = oper->oper.utimens ? cache_utimens : NULL;
         cache_oper.write    = oper->oper.write ? cache_write : NULL;
         cache_oper.create   = oper->oper.create ? cache_create : NULL;
+        // TODO: cache `readdir`
         pthread_mutex_init(&cache.lock, NULL);
         cache.table = g_hash_table_new_full(g_str_hash, g_str_equal, g_free,
                                             free_node);

cache.h

@@ -23,7 +23,6 @@ typedef int (*fuse_cache_dirfil_t) (fuse_cache_dirh_t h, const char *name,
 
 struct fuse_cache_operations {
     struct fuse_operations oper;
-    int (*cache_getdir) (const char *, fuse_cache_dirh_t, fuse_cache_dirfil_t);
 };
 
 struct fuse_operations *cache_init(struct fuse_cache_operations *oper);

ftpfs-ls.c

@@ -190,7 +190,7 @@ static int parse_dir_netware(const char *line,
 int parse_dir(const char* list, const char* dir,
               const char* name, struct stat* sbuf,
               char* linkbuf, int linklen,
-              fuse_cache_dirh_t h, fuse_cache_dirfil_t filler) {
+              void *dbuf, fuse_cache_dirfil_t filler) {
   char *file;
   char *link;
   const char *start = list;
@@ -253,9 +253,9 @@ int parse_dir(const char* list, const char* dir,
         free(reallink);
       }
 
-      if (h && filler) {
+      if (dbuf && filler) {
         DEBUG(1, "filler: %s\n", file);
-        filler(h, file, &stat_buf);
+        filler(dbuf, file, &stat_buf);
       } else {
         DEBUG(1, "cache_add_attr: %s\n", full_path);
         cache_add_attr(full_path, &stat_buf);

ftpfs-ls.h

@@ -14,6 +14,6 @@
 int parse_dir(const char* list, const char* dir,
               const char* name, struct stat* sbuf,
               char* linkbuf, int linklen,
-              fuse_cache_dirh_t h, fuse_cache_dirfil_t filler);
+              void *dbuf, fuse_cache_dirfil_t filler);
 
 #endif  /* __CURLFTPFS_FTPFS_LS_H__ */

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),
@@ -266,13 +267,17 @@ static size_t read_data(void *ptr, size_t size, size_t nmemb, void *data) {
     }\
   }while(0)
 
-static int ftpfs_getdir(const char* path, fuse_cache_dirh_t h,
-                        fuse_cache_dirfil_t filler) {
+static int ftpfs_readdir(const char* path, void *dbuf, fuse_fill_dir_t filler,
+                         off_t offset, struct fuse_file_info *fi,
+                         enum fuse_readdir_flags flags) {
+  // N.B.: fuse.h tells us that we can ignore `offset` and pass 0 to the filler where it would expect an offset.
+  // fuse_cache_dirfil_t handle = (struct dir_handle*) fi->fh;  //< set by us in `open`
+
   int err = 0;
   CURLcode curl_res;
   char* dir_path = get_fulldir_path(path);
 
-  DEBUG(1, "ftpfs_getdir: %s\n", dir_path);
+  DEBUG(1, "ftpfs_readdir: %s\n", dir_path);
   struct buffer buf;
   buf_init(&buf);
 
@@ -289,12 +294,12 @@ static int ftpfs_getdir(const char* path, fuse_cache_dirh_t h,
   } else {
     buf_null_terminate(&buf);
     parse_dir((char*)buf.p, dir_path + strlen(ftpfs.host) - 1,
-              NULL, NULL, NULL, 0, h, filler); 
+              NULL, NULL, NULL, 0, dbuf, filler);
   }
 
   free(dir_path);
   buf_free(&buf);
-  return op_return(err, "ftpfs_getdir");
+  return op_return(err, "ftpfs_readdir");
 }
 
 static int ftpfs_getattr(const char* path, struct stat* sbuf, struct fuse_file_info* fi) {
@@ -1361,6 +1366,15 @@ static int ftpfs_statfs(const char *path, struct statvfs *buf)
     return op_return(0, "ftpfs_statfs");
 }
 
+// static void *ftpfs_init(struct fuse_conn_info *conn,
+//                         struct fuse_config *cfg)
+// {
+//   // alternatively, mount with `-o readdirplus=no`
+//   conn->want &= ~FUSE_CAP_READDIRPLUS;
+//   // alternatively, mount with `-o sync_read`
+//   conn->want &= ~FUSE_CAP_ASYNC_READ;
+// }
+
 static struct fuse_cache_operations ftpfs_oper = {
   .oper = {
 //    .init       = ftpfs_init,
@@ -1384,8 +1398,8 @@ static struct fuse_cache_operations ftpfs_oper = {
     .write      = ftpfs_write,
     .statfs     = ftpfs_statfs,
     .create     = ftpfs_create,
+    .readdir    = ftpfs_readdir,
   },
-  .cache_getdir = ftpfs_getdir,
 };
 
 static int curlftpfs_fuse_main(struct fuse_args *args)
@@ -1489,6 +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"
@@ -1787,7 +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;