cmFileSys.h/c: Added cmFileSysCanWriteToDir() and cmFsCanWriteToDir().

cmFileSys.c

@@ -248,6 +248,24 @@ bool _cmFileSysIsDir( cmFs_t* p, const cmChar_t* dirStr )
   return S_ISDIR(s.st_mode);
 }
 
+bool cmFileSysCanWriteToDir( cmFileSysH_t h, const cmChar_t* dirStr )
+{
+  cmFs_t*     p = _cmFileSysHandleToPtr(h);
+  int result;
+
+  errno = 0;
+
+  if((result = access(dirStr,W_OK)) == 0 )
+    return true;
+
+  if( result == EACCES || result==EROFS )
+    return false;
+
+  _cmFileSysError( p, kAccessFailFsRC, errno, "'access' failed on '%s'.",dirStr);
+
+  return false;  
+}
+
 bool cmFileSysIsDir( cmFileSysH_t h, const cmChar_t* dirStr )
 {
   cmFs_t*     p = _cmFileSysHandleToPtr(h);
@@ -1129,6 +1147,9 @@ const cmChar_t*      cmFsRsrcDir()
 const cmChar_t*      cmFsUserDir()
 { return cmFileSysUserDir(_cmFsH); }
 
+bool                cmFsCanWriteToDir( const cmChar_t* dirStr )
+{ return cmFileSysCanWriteToDir(_cmFsH,dirStr); }
+
 bool                 cmFsIsDir(  const cmChar_t* dirStr )
 { return cmFileSysIsDir(_cmFsH,dirStr); }
 

cmFileSys.h

@@ -36,6 +36,7 @@ extern "C" {
     kLinuxFailFsRC,
     kInvalidDirFsRC,
     kGenFileFailFsRC,
+    kAccessFailFsRC
   };
 
 
@@ -65,6 +66,9 @@ extern "C" {
   const cmChar_t* cmFileSysRsrcDir(  cmFileSysH_t h ); //< Return the operating system dependent application resource directory for this application.
   const cmChar_t* cmFileSysUserDir(  cmFileSysH_t h ); //< Return the operating system dependent user directory for this application.
 
+  // Check if a request to create a file will succeed.
+  bool cmFileSysCanWriteToDir( cmFileSysH_t h, const cmChar_t* dirStr );
+
   // Test the type of a file system object:
   //
   bool     cmFileSysIsDir(  cmFileSysH_t h, const cmChar_t* dirStr ); //< Return true if 'dirStr' refers to an existing directory.
@@ -203,6 +207,8 @@ extern "C" {
   const cmChar_t* cmFsRsrcDir();
   const cmChar_t* cmFsUserDir();
 
+  bool            cmFsCanWriteToDir( const cmChar_t* dirStr );
+
   bool            cmFsIsDir(  const cmChar_t* dirStr );
   bool            cmFsIsFile( const cmChar_t* fnStr ); 
   bool            cmFsIsLink( const cmChar_t* fnStr );