diff --git a/cmFileSys.c b/cmFileSys.c
index 9cd8147..9a96583 100644
--- a/cmFileSys.c
+++ b/cmFileSys.c
@@ -7,6 +7,7 @@
 #include "cmMallocDebug.h"
 #include "cmLinkedHeap.h"
 #include "cmFileSys.h"
+#include "cmText.h"
 
 #include <sys/stat.h>
 #include <errno.h>
@@ -467,6 +468,45 @@ void cmFileSysFreeFn( cmFileSysH_t h, const cmChar_t* fn )
   cmLHeapFree(p->heapH, (void*)fn); 
 }
 
+cmFsRC_t cmFileSysGenFn( cmFileSysH_t h, const cmChar_t* dir, const cmChar_t* prefixStr, const cmChar_t* extStr, const cmChar_t** fnPtr )
+{
+  cmFsRC_t rc            = kOkFsRC;
+  cmFs_t*  p             = _cmFileSysHandleToPtr(h);
+  unsigned maxAttemptCnt = 0xffff;
+
+  *fnPtr = NULL;
+
+  assert(dir != NULL);
+
+  if( prefixStr == NULL )
+    prefixStr = "";
+
+  if( extStr == NULL )
+    extStr = "";
+
+  if( !cmFileSysIsDir(h,dir) )
+    return cmErrMsg(&p->err,kOpenDirFailFsRC,"File name generation failed because the directory '%s' does not exist.",cmStringNullGuard(dir));
+
+  unsigned i;
+  for(i=0; *fnPtr==NULL; ++i)
+  {
+    cmChar_t* fn = cmTsPrintfP(NULL,"%s%i",prefixStr,i);
+
+    const cmChar_t* path = cmFileSysMakeFn(h,dir,fn,extStr,NULL );
+    
+    if( !cmFileSysIsFile(h,path) )
+      *fnPtr = cmMemAllocStr(path);
+
+    cmFileSysFreeFn(h,path);
+    cmMemFree(fn);
+
+    if( i == maxAttemptCnt )
+      return cmErrMsg(&p->err,kGenFileFailFsRC,"File name generation failed because a suitable file name could not be found after %i attempts.",maxAttemptCnt);
+  };
+
+  return rc;
+}
+
 cmFsRC_t    cmFileSysMkDir( cmFileSysH_t h, const cmChar_t* dir )
 {
   cmFs_t* p = _cmFileSysHandleToPtr(h);
@@ -1113,6 +1153,9 @@ const cmChar_t*      cmFsMakeFn(  const cmChar_t* dirPrefix, const cmChar_t* fn,
 void                 cmFsFreeFn(  const cmChar_t* fn )
 { cmFileSysFreeFn(_cmFsH, fn); }
 
+cmFsRC_t             cmFsGenFn( const cmChar_t* dir, const cmChar_t* prefixStr, const cmChar_t* extStr, const cmChar_t** fnPtr )
+{ return cmFileSysGenFn(_cmFsH,dir,prefixStr,extStr,fnPtr); }
+
 cmFsRC_t             cmFsMkDir( const cmChar_t* dir )
 { return cmFileSysMkDir(_cmFsH,dir); }
 
diff --git a/cmFileSys.h b/cmFileSys.h
index 71488c7..e67dca9 100644
--- a/cmFileSys.h
+++ b/cmFileSys.h
@@ -34,7 +34,8 @@ extern "C" {
     kSysErrFsRC,
     kOsxFailFsRC,
     kLinuxFailFsRC,
-    kInvalidDirFsRC
+    kInvalidDirFsRC,
+    kGenFileFailFsRC
   };
 
 
@@ -89,6 +90,12 @@ extern "C" {
   // Release the file name created through an earlier call to cmFileSysMakeFn().
   void            cmFileSysFreeFn( cmFileSysH_t h, const cmChar_t* fn );
 
+  // Generate an unused filename in the directory 'dir' beginning with the prefix 'prefixStr'.
+  // The returned file name will have the format: <dir>/<prefixStr>nnnn.<extStr> where
+  // nnn represents 1 or more digits.  The returned string must be released with a 
+  // call to cmMemFree().
+  cmFsRC_t cmFileSysGenFn( cmFileSysH_t h, const cmChar_t* dir, const cmChar_t* prefixStr, const cmChar_t* extStr, const cmChar_t** fnPtr );
+
   // Create a directory - where the entire path already exists except for the 
   // final directory.
   cmFsRC_t    cmFileSysMkDir( cmFileSysH_t h, const cmChar_t* dir );
@@ -178,6 +185,7 @@ extern "C" {
   // Release the memory assoicated with a cmFileSysDirEntry_t array returned from an earlier call to cmFileSysDirEntries().
   void cmFileSysDirFreeEntries( cmFileSysH_t h, cmFileSysDirEntry_t* p );
 
+
   // Return the last error code generated by the file system.
   cmFsRC_t cmFileSysErrorCode( cmFileSysH_t h );
 
@@ -202,6 +210,8 @@ extern "C" {
   const cmChar_t* cmFsVMakeFn( const cmChar_t* dirPrefix, const cmChar_t* fn, const cmChar_t* ext, va_list vl );
   const cmChar_t* cmFsMakeFn(  const cmChar_t* dirPrefix, const cmChar_t* fn, const cmChar_t* ext, ... );
   void            cmFsFreeFn(  const cmChar_t* fn );
+  cmFsRC_t        cmFsGenFn(  const cmChar_t* dir, const cmChar_t* prefixStr, const cmChar_t* extStr, const cmChar_t** fnPtr );
+
 
   cmFsRC_t        cmFsMkDir( const cmChar_t* dir );
   cmFsRC_t        cmFsMkDirAll( const cmChar_t* dir );