ftruncate
    (PHP 4 )
ftruncate -- Truncates a file to a given length
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:        Prior to PHP 4.3.3, ftruncate() returns an        integer value of 1 on success, instead of        boolean TRUE.      
     See also fopen() and       fseek().