SED is shorter (0 byte). SED /is/ a turing complete language [1] so don't try to claim that I'm cheating.
sed < input > output
[1] http://robertkotcher.com/sed.html
[update] s/set/sed/
The command line equivalent, with Perl:
perl -pe '' <input >output
Re:Copying stdin to stdout in Java
by Alphasite_ on Wednesday March 26, 2014 @06:07AM
(#7472471)
Even java can do that setOut(system.in); (iirc)
> Even java can do that setOut(system.in);
I was referring to an empty SED-program that would then be run via 'sed -f empty-file.sed'. Of course you need >0 bytes to invoke the SED program.
Still the shortest Perl is 0 bytes when the command line switch is allowed to be -p
Update: That's actually called "the sed mode of Perl." Moreover these two command lines behave similarly:
and