# args: ($file, $buffer, $length) # returns data in $buffer and number of bytes read, or undef on EOF sub sysreadfull { my ($file, $len) = ($_[0], $_[2]); my $n = 0; while ($len - $n) { my $i = sysread($file, $_[1], $len - $n, $n); if (defined($i)) { if ($i == 0) { return $n; } else { $n += $i; } } elsif ($!{EINTR}) { redo; } else { return $n ? $n : undef; } } return $n; } # args: ($file, $buffer) # returns number of bytes actually written sub syswritefull { my ($file, $len) = ($_[0], length($_[1])); my $n = 0; while ($len - $n) { my $i = syswrite($file, $_[1], $len - $n, $n); if (defined($i)) { $n += $i; } elsif ($!{EINTR}) { redo; } else { return $n ? $n : undef; } } return $n; }