I was looking in the code for copy_file() and noticed what may be a bug. In the loop that handles partial writes, the code makes multiple attempts reducing the amount of data written each time. Unfortunately, the offset into the data is not changed as well. See below. sz_write = 0; do { if ( (sz = ::write( outfile, buf.get(), sz_read - sz_write )) < 0 ) { sz_read = sz; // cause read loop termination break; // and error to be thrown after closes } sz_write += sz; } while ( sz_write < sz_read ); Unless I'm missing something, it looks like a partial write will result in the first part of the buffer being written multiple times. I checked the version in CVS and it appears to have the same code. Am I missing something or is this incorrect? G. Wade