doveadm: Give a better error message if we can guess that unknown command is due...

diff --git a/src/doveadm/doveadm.c b/src/doveadm/doveadm.c
index 595367533d226268b7a7a91841f9ef40684e7670..69fcec1dfdc9cf4a79df7f59e8eab2193f82cc44 100644 (file)
--- a/src/doveadm/doveadm.c
+++ b/src/doveadm/doveadm.c
@@ -17,6 +17,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <dirent.h>
 #include <time.h>
 #include <sys/stat.h>
 
@@ -209,6 +210,41 @@ static bool doveadm_has_subcommands(const char *cmd_name)
        return doveadm_mail_has_subcommands(cmd_name);
 }
 
+static bool doveadm_has_unloaded_plugin(const char *name)
+{
+       struct module *module;
+       DIR *dir;
+       struct dirent *d;
+       const char *plugin_name;
+       unsigned int name_len = strlen(name);
+       bool found = FALSE;
+
+       /* first check that it's not actually loaded */
+       for (module = modules; module != NULL; module = module->next) {
+               if (strcmp(module_get_plugin_name(module), name) == 0)
+                       return FALSE;
+       }
+
+       dir = opendir(DOVEADM_MODULEDIR);
+       if (dir == NULL)
+               return FALSE;
+
+       while ((d = readdir(dir)) != NULL) {
+               plugin_name = module_file_get_name(d->d_name);
+               if (strncmp(plugin_name, "doveadm_", 8) == 0)
+                       plugin_name += 8;
+
+               if (strncmp(plugin_name, name, name_len) == 0 &&
+                   (plugin_name[name_len] == '\0' ||
+                    strcmp(plugin_name + name_len, "_plugin") == 0)) {
+                       found = TRUE;
+                       break;
+               }
+       }
+       (void)closedir(dir);
+       return found;
+}
+
 static void cmd_help(int argc ATTR_UNUSED, char *argv[])
 {
        const char *man_argv[3];
@@ -426,8 +462,13 @@ int main(int argc, char *argv[])
 
        if (!doveadm_try_run(cmd_name, argc, argv) &&
            !doveadm_mail_try_run(cmd_name, argc, argv)) {
-               if (doveadm_has_subcommands(argv[0]))
-                       usage_to(stdout, argv[0]);
+               if (doveadm_has_subcommands(cmd_name))
+                       usage_to(stdout, cmd_name);
+               if (doveadm_has_unloaded_plugin(cmd_name)) {
+                       i_fatal("Unknown command '%s', but plugin %s exists. "
+                               "Try to set mail_plugins=%s",
+                               cmd_name, cmd_name, cmd_name);
+               }
                usage();
        }