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

问题

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

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

回答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.

回答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.

来源：https://stackoverflow.com/questions/3517250/how-do-i-detect-if-stdout-is-connected-to-a-tty-in-perl