Description
bool 
ftruncate ( resource handle, int size )
     Takes the filepointer, handle, and truncates the file to 
     length, size. Returns TRUE on success or FALSE on failure.
    
Note: 
      The file pointer is changed only in append mode. In
      write mode, additional fseek()
      call is needed.
     
Note: 
      Prior to PHP 4.3.3, ftruncate() returns an 
      integer value of 1 on success, instead of 
      boolean TRUE.
     
     See also fopen() and 
     fseek().