How do I detect if stdout is connected to a tty in Perl?

Question

I'm looking for the Perl equivalent to this Python code:

from sys import stdout
if stdout.isatty():
    print "yes"
else:
    print "no"

Answer 1

Use the -t filetest operator.

print -t STDOUT ? "Yes\n" : "No\n"

Note that in Perl, STDOUT can be tied (essentially an overcomplicated overloaded object) so output to STDOUT may still reach a TTY even if its not directly attached to one.

Answer 2

Use IO::interactive if you require STDOUT to actually be connected to the terminal, and not just being redirected to /dev/null/ or whatever.