Implements the fcntl(2) function. You'll probably have to say
- use Fcntl;
first to get the correct constant definitions. Argument processing and
value returned work just like
You don't have to check for
defined on the return from
ioctl, it maps a
return from the system call into
"0 but true"
in Perl. This string is true in boolean context and
in numeric context. It is also exempt from the normal -w warnings
on improper numeric conversions.
fcntl raises an exception if used on a machine that
doesn't implement fcntl(2). See the Fcntl module or your fcntl(2)
manpage to learn what functions are available on your system.
Here's an example of setting a filehandle named
non-blocking at the system level. You'll have to negotiate
on your own, though.
Portability issues: fcntl in perlport.