1 files changed, 121 insertions, 0 deletions
diff --git a/fish/tilde.c b/fish/tilde.c
new file mode 100644
index 00000000..13e6cd8f
--- /dev/null
+++ b/fish/tilde.c
@@ -0,0 +1,121 @@
+/* guestfish - the filesystem interactive shell
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * This program 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 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <assert.h>
+#include <pwd.h>
+#include <sys/types.h>
+
+#include "fish.h"
+
+static char *expand_home (const char *);
+static const char *find_home_for_username (const char *, int);
+
+/* This is called from the script loop if we find a candidate for
+ * ~username (tilde-expansion).
+ */
+char *
+try_tilde_expansion (char *str)
+{
+  assert (str[0] == '~');
+
+  /* Expand current user's home directory.  By simple experimentation
+   * I found out that bash always uses $HOME.
+   */
+  if (str[1] == '\0')		/* ~ */
+    return expand_home (NULL);
+  else if (str[1] == '/')	/* ~/... */
+    return expand_home (&str[1]);
+
+  /* Try expanding the part up to the following '\0' or '/' as a
+   * username from the password file.
+   */
+  else {
+    int len;
+    const char *home, *rest;
+
+    len = strcspn (&str[1], "/");
+    rest = &str[1+len];
+
+    home = find_home_for_username (&str[1], len);
+
+    if (home) {
+      len = strlen (home) + strlen (rest);
+      str = malloc (len);
+      if (str == NULL) {
+	perror ("malloc");
+	exit (1);
+      }
+      strcpy (str, home);
+      strcat (str, rest);
+      return str;
+    }
+  }
+
+  /* No match, return the orignal string. */
+  return str;
+}
+
+/* Return $HOME + append string. */
+static char *
+expand_home (const char *append)
+{
+  const char *home;
+  int len;
+  char *str;
+
+  home = getenv ("HOME");
+  if (!home) home = "~";
+
+  len = strlen (home) + (append ? strlen (append) : 0);
+  str = malloc (len);
+  if (str == NULL) {
+    perror ("malloc");
+    exit (1);
+  }
+
+  strcpy (str, home);
+  if (append)
+    strcat (str, append);
+
+  return str;
+}
+
+/* Lookup username (of length ulen), return home directory if found,
+ * or NULL if not found.
+ */
+static const char *
+find_home_for_username (const char *username, int ulen)
+{
+  struct passwd *pw;
+
+  setpwent ();
+  while ((pw = getpwent ()) != NULL) {
+    if (strlen (pw->pw_name) == ulen &&
+	strncmp (username, pw->pw_name, ulen) == 0)
+      return pw->pw_dir;
+  }
+
+  return NULL;
+}