From e01cdf2065d93cdbb873999b45414133978860b2 Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Mon, 12 Mar 2007 13:50:28 -0400
Subject: [PATCH] ENH: Added kwsys SystemTools::CreateSymlink and
 SystemTools::ReadSymlink.

---
 Source/cmSystemTools.cxx        | 14 ------------
 Source/cmSystemTools.h          |  1 -
 Source/kwsys/SystemTools.cxx    | 38 +++++++++++++++++++++++++++++++++
 Source/kwsys/SystemTools.hxx.in | 12 +++++++++++
 4 files changed, 50 insertions(+), 15 deletions(-)

diff --git a/Source/cmSystemTools.cxx b/Source/cmSystemTools.cxx
index 530d7fdf82..355325976b 100644
--- a/Source/cmSystemTools.cxx
+++ b/Source/cmSystemTools.cxx
@@ -1376,20 +1376,6 @@ bool cmSystemTools::StringEndsWith(const char* str1, const char* str2)
   return !strncmp(str1 + (strlen(str1)-strlen(str2)), str2, strlen(str2));
 }
 
-#if defined(_WIN32) && !defined(__CYGWIN__)
-bool cmSystemTools::CreateSymlink(const char*, const char*)
-{
-  // Should we create a copy here?
-  return false;
-}
-#else
-bool cmSystemTools::CreateSymlink(const char* origName, const char* newName)
-{
-  return (symlink(origName, newName) >= 0);
-}
-#endif
-
-
 // compute the relative path from here to there
 std::string cmSystemTools::RelativePath(const char* local, const char* remote)
 {
diff --git a/Source/cmSystemTools.h b/Source/cmSystemTools.h
index 1838039dbb..f785358c4f 100644
--- a/Source/cmSystemTools.h
+++ b/Source/cmSystemTools.h
@@ -297,7 +297,6 @@ public:
   static std::string ConvertToRunCommandPath(const char* path);
   //! Check if the first string ends with the second one.
   static bool StringEndsWith(const char* str1, const char* str2);
-  static bool CreateSymlink(const char* origName, const char* newName);
   
   /** compute the relative path from local to remote.  local must 
       be a directory.  remote can be a file or a directory.  
diff --git a/Source/kwsys/SystemTools.cxx b/Source/kwsys/SystemTools.cxx
index 9892d73482..9212b459f4 100644
--- a/Source/kwsys/SystemTools.cxx
+++ b/Source/kwsys/SystemTools.cxx
@@ -2356,6 +2356,44 @@ bool SystemTools::FileIsSymlink(const char* name)
 #endif
 }
 
+#if defined(_WIN32) && !defined(__CYGWIN__)
+bool SystemTools::CreateSymlink(const char*, const char*)
+{
+  return false;
+}
+#else
+bool SystemTools::CreateSymlink(const char* origName, const char* newName)
+{
+  return symlink(origName, newName) >= 0;
+}
+#endif
+
+#if defined(_WIN32) && !defined(__CYGWIN__)
+bool SystemTools::ReadSymlink(const char*, kwsys_stl::string&)
+{
+  return false;
+}
+#else
+bool SystemTools::ReadSymlink(const char* newName,
+                              kwsys_stl::string& origName)
+{
+  char buf[KWSYS_SYSTEMTOOLS_MAXPATH+1];
+  int count =
+    static_cast<int>(readlink(newName, buf, KWSYS_SYSTEMTOOLS_MAXPATH));
+  if(count >= 0)
+    {
+    // Add null-terminator.
+    buf[count] = 0;
+    origName = buf;
+    return true;
+    }
+  else
+    {
+    return false;
+    }
+}
+#endif
+
 int SystemTools::ChangeDirectory(const char *dir)
 {
   return Chdir(dir);
diff --git a/Source/kwsys/SystemTools.hxx.in b/Source/kwsys/SystemTools.hxx.in
index 054666fed7..c89bd493bc 100644
--- a/Source/kwsys/SystemTools.hxx.in
+++ b/Source/kwsys/SystemTools.hxx.in
@@ -588,6 +588,18 @@ public:
     unsigned long length = 256, 
     double percent_bin = 0.05);
 
+  /**
+   * Create a symbolic link if the platform supports it.  Returns whether
+   * creation succeded.
+   */
+  static bool CreateSymlink(const char* origName, const char* newName);
+
+  /**
+   * Read the contents of a symbolic link.  Returns whether reading
+   * succeded.
+   */
+  static bool ReadSymlink(const char* newName, kwsys_stl::string& origName);
+
   /**
    * Try to locate the file 'filename' in the directory 'dir'.
    * If 'filename' is a fully qualified filename, the basename of the file is