cmd/flux-kvs: add flux kvs dirat

Add flux-kvs dirat [-r] treeobj key

This command demonstrates walking a snapshot using
kvs_get_dirat(), kvs_get_symlinkat(), and kvs_getat().

src/cmd/flux-kvs.c

@@ -67,6 +67,7 @@ void cmd_dirsize (flux_t h, int argc, char **argv);
 void cmd_get_treeobj (flux_t h, int argc, char **argv);
 void cmd_put_treeobj (flux_t h, int argc, char **argv);
 void cmd_getat (flux_t h, int argc, char **argv);
+void cmd_dirat (flux_t h, int argc, char **argv);
 
 
 void usage (void)
@@ -95,6 +96,7 @@ void usage (void)
 "       flux-kvs get-treeobj     key\n"
 "       flux-kvs put-treeobj     key=treeobj\n"
 "       flux-kvs getat           treeobj key\n"
+"       flux-kvs dirat [-r]      treeobj [key]\n"
 );
     exit (1);
 }
@@ -170,6 +172,8 @@ int main (int argc, char *argv[])
         cmd_put_treeobj (h, argc - optind, argv + optind);
     else if (!strcmp (cmd, "getat"))
         cmd_getat (h, argc - optind, argv + optind);
+    else if (!strcmp (cmd, "dirat"))
+        cmd_dirat (h, argc - optind, argv + optind);
     else
         usage ();
 
@@ -609,6 +613,63 @@ void cmd_dir (flux_t h, int argc, char **argv)
         log_msg_exit ("dir: specify zero or one directory");
 }
 
+static void dump_kvs_dirat (flux_t h, bool ropt,
+                            const char *treeobj, const char *path)
+{
+    kvsdir_t *dir;
+    kvsitr_t *itr;
+    const char *name;
+    char *key;
+
+    if (kvs_get_dirat (h, treeobj, path, &dir) < 0)
+        log_err_exit ("%s", path);
+
+    itr = kvsitr_create (dir);
+    while ((name = kvsitr_next (itr))) {
+        key = kvsdir_key_at (dir, name);
+        if (kvsdir_issymlink (dir, name)) {
+            char *link;
+            if (kvs_get_symlinkat (h, treeobj, key, &link) < 0)
+                log_err_exit ("%s", key);
+            printf ("%s -> %s\n", key, link);
+            free (link);
+
+        } else if (kvsdir_isdir (dir, name)) {
+            if (ropt)
+                dump_kvs_dirat (h, ropt, treeobj, key);
+            else
+                printf ("%s.\n", key);
+        } else {
+            char *json_str;
+            if (kvs_getat (h, treeobj, key, &json_str) < 0)
+                log_err_exit ("%s", key);
+            dump_kvs_val (key, json_str);
+            free (json_str);
+        }
+        free (key);
+    }
+    kvsitr_destroy (itr);
+    kvsdir_destroy (dir);
+
+}
+
+void cmd_dirat (flux_t h, int argc, char **argv)
+{
+    bool ropt = false;
+
+    if (argc > 0 && !strcmp (argv[0], "-r")) {
+        ropt = true;
+        argc--;
+        argv++;
+    }
+    if (argc == 1)
+        dump_kvs_dirat (h, ropt, argv[0], ".");
+    else if (argc == 2)
+        dump_kvs_dirat (h, ropt, argv[0], argv[1]);
+    else
+        log_msg_exit ("dirat: specify treeobj and zero or one directory");
+}
+
 void cmd_dirsize (flux_t h, int argc, char **argv)
 {
     kvsdir_t *dir = NULL;