From 92b88ad62cefc6aa9029906eccdbdf8643ec8914 Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Fri, 30 Jan 2015 13:42:27 +0100
Subject: [PATCH] utils os: Add sdb_realpath().

This function is similar to realpath() but also expands ~/ to the current
user's home directory.
---
 src/include/utils/os.h | 16 ++++++++++++++++
 src/utils/os.c         | 23 +++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/src/include/utils/os.h b/src/include/utils/os.h
index f4decde..42fdea3 100644
--- a/src/include/utils/os.h
+++ b/src/include/utils/os.h
@@ -47,6 +47,22 @@ extern "C" {
 char *
 sdb_get_homedir(void);
 
+/*
+ * sdb_realpath:
+ * Returns the canonicalized absolute pathname for the specified path. The
+ * function expands all symbolic links and resolves references to '.', '..',
+ * and extra slash characters (/).
+ *
+ * '~/' at the start of the string will be replaced by the current user's home
+ * directory.
+ *
+ * Returns:
+ *  - the canonicalized absolute pathname on success
+ *  - NULL else
+ */
+char *
+sdb_realpath(const char *path);
+
 /*
  * sysdb_mkdir_all:
  * Recursively create the directory 'pathname' (similar to 'mkdir -p' on the
diff --git a/src/utils/os.c b/src/utils/os.c
index e975f96..c94e271 100644
--- a/src/utils/os.c
+++ b/src/utils/os.c
@@ -84,6 +84,29 @@ sdb_get_homedir(void)
 	return strdup(result->pw_dir);
 } /* sdb_get_homedir */
 
+char *
+sdb_realpath(const char *path)
+{
+	if (! path)
+		return NULL;
+
+	if ((strlen(path) >= 2) && (path[0] == '~') && (path[1] == '/')) {
+		char *homedir = sdb_get_homedir();
+		char tmp[(homedir ? strlen(homedir) : 0) + strlen(path)];
+		char *ret;
+
+		if (! homedir)
+			return NULL;
+
+		snprintf(tmp, sizeof(tmp), "%s/%s", homedir, path + 2);
+		ret = realpath(tmp, NULL);
+		free(homedir);
+		return ret;
+	}
+
+	return realpath(path, NULL);
+} /* sdb_realpath */
+
 int
 sdb_mkdir_all(const char *pathname, mode_t mode)
 {
-- 
2.30.2