A Easy Example-to-tell-you-are "2>&1" in Perl

You can decide if make the output shown on command screens by using 2>&1 or NUL

Testing script:

print "without null \ n";

System ("dir 2>&1");

print "with null \ n";

System ("dir > NUL");

print "End \ n";

Result:

C:\rebecca\script\perl\unicode>perl calculate.pl

Without null

Volume in drive C Isosdisk

Volume Serial Numberis ba23-5612

Directory of C:\Rebecca\script\perl\Unicode

01/22/2015 04:59pm <DIR>.

01/22/2015 04:59pm <DIR>.

01/22/2015 04:58pm 227 calculate.pl

01/22/2015 09:19am 194 unicode_test_v1.pl

01/21/2015 05:23pm 193unicode_test_v1.pl.ba

3File (s) 614 bytes

2Dir (s) 175,476,535,296 bytes free

With null #you can see with NUL, there isn ' t any output shown here

End

A Easy Example-to-tell-you-are "2>&1" in Perl