bash pipestatus in backticked command?

Question

in bash, if I execute a couple of commands piped together inside of backticks, how can I find out the exit status of the first command?

i.e. in this case, I am tryin

Answer 1

Try to set pipefail option. It returns the last command of the pipeline that failed. One example:

First I disable it:

set +o pipefail

Create a perl script (script.pl) to test the pipeline:

#!/usr/bin/env perl

use warnings;
use strict;

if ( @ARGV ) { 
    die "Line1\nLine2\nLine3\n";
}
else {
    print "Line1\nLine2\nLine3\n";
}

Run in command-line:

myvar=`perl script.pl | tail -1`
echo $? "$myvar"

That yields:

0 Line3

It seems correct, let see with pipefail enabled:

set -o pipefail

And run the command:

myvar=`perl script.pl fail 2>&1 | tail -1`
echo $? "$myvar"

That yields:

255 Line3