1 files changed, 128 insertions, 0 deletions
diff --git a/dircat.c b/dircat.c
new file mode 100644
index 0000000..5a60899
--- /dev/null
+++ b/dircat.c
@@ -0,0 +1,128 @@
+/* Hurd /proc filesystem, concatenation of two directories.
+   Copyright (C) 2010 Free Software Foundation, Inc.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd 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.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <stdlib.h>
+#include <string.h>
+#include "procfs.h"
+
+struct dircat_node
+{
+  int num_dirs;
+  struct node *dirs[0];
+};
+
+static error_t
+dircat_get_contents (void *hook, char **contents, ssize_t *contents_len)
+{
+  struct dircat_node *dcn = hook;
+  int i, sz, pos;
+  error_t err;
+
+  pos = 0;
+  *contents = malloc (sz = 512);
+
+  for (i=0; i < dcn->num_dirs; i++)
+    {
+      char *subcon;
+      ssize_t sublen;
+
+      /* Make sure we're not getting some old stuff.  */
+      procfs_refresh (dcn->dirs[i]);
+
+      err = procfs_get_contents (dcn->dirs[i], &subcon, &sublen);
+      if (err)
+        {
+	  free (*contents);
+	  *contents = NULL;
+	  return err;
+	}
+
+      while (pos + sublen > sz)
+	*contents = realloc (*contents, sz *= 2);
+
+      memcpy (*contents + pos, subcon, sublen);
+      pos += sublen;
+    }
+
+  *contents_len = pos;
+  return 0;
+}
+
+static error_t
+dircat_lookup (void *hook, const char *name, struct node **np)
+{
+  struct dircat_node *dcn = hook;
+  error_t err;
+  int i;
+
+  err = ENOENT;
+  for (i=0; err && i < dcn->num_dirs; i++)
+    err = procfs_lookup (dcn->dirs[i], name, np);
+
+  return err;
+}
+
+static void
+dircat_release_dirs (struct node *const *dirs, int num_dirs)
+{
+  int i;
+
+  for (i=0; i < num_dirs; i++)
+    if (dirs[i])
+      netfs_nrele (dirs[i]);
+}
+
+static void
+dircat_cleanup (void *hook)
+{
+  struct dircat_node *dcn = hook;
+
+  dircat_release_dirs (dcn->dirs, dcn->num_dirs);
+  free (dcn);
+}
+
+struct node *
+dircat_make_node (struct node *const *dirs, int num_dirs)
+{
+  static struct procfs_node_ops ops = {
+    .get_contents = dircat_get_contents,
+    .cleanup_contents = procfs_cleanup_contents_with_free,
+    .lookup = dircat_lookup,
+    .cleanup = dircat_cleanup,
+  };
+  struct dircat_node *dcn;
+  int i;
+
+  for (i=0; i < num_dirs; i++)
+    if (! dirs[i])
+      goto fail;
+
+  dcn = malloc (sizeof *dcn + num_dirs * sizeof dcn->dirs[0]);
+  if (! dcn)
+    goto fail;
+
+  dcn->num_dirs = num_dirs;
+  memcpy (dcn->dirs, dirs, num_dirs * sizeof dcn->dirs[0]);
+  return procfs_make_node (&ops, dcn);
+
+fail:
+  dircat_release_dirs (dirs, num_dirs);
+  return NULL;
+}
+