But I do encounter such a question:

case 1:

 use strict;  my $cmd = "dumpcap -i eth0 -b duration:10 -w \\media\\Work\\abc.pcap";  `$cmd`

"dumpcap" itself will print some infomation, if I add 2>&1 behind $cmd, such as `$cmd 2>&1`, no infomation displayed. But if I do not add 2>&1, information do displays

in another case, If I change $cmd to :

 my $cmd = "ifconfig";

There is no information displayed in shell no matter If I add 2>&1 or not

Why is this difference ?

In reply to Re^2: how does '2>&1' work ? by wildnature
in thread how does '2>&1' work ? by wildnature

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