Perl Unable to truncate string - string

Question

I am trying to extract AAA and BBB from the output of the command "dspmq".
$dspmq <- this command gives output as -->
QMNAME(AAA) STATUS(Running)
QMNAME(BBB) STATUS(Running)
But it doesn't work with the below code.
perl -e 'use Data::Dumper qw(Dumper);my #qmgrlist = `dspmq`;$size = #qmgrlist;foreach my $i (#qmgrlist){my #temp1 = split /QMNAME\(/, $i;print #temp1;}'
AAA) STATUS(Running)
BBB) STATUS(Running)
I am able to truncate "QMNAME(" but unable to truncate those to the right of AAA and BBB. Basically I want to get the string between "QMNAME(" and the immediate ")". Please assist.

Answer 1

I think a regex approach is better than split() here, but you could use split() by splitting on parentheses and taking the second item in the returned list.
for (#qmgrlist) {
say +(split /[()]/)[0];
}
And a brief note on your use of command-line options to run this code. You can make it simpler if you a) pipe the output of qspmq into your code and b) use -n to process a record at a time.
$ perl -nE 'say +(split /[()]/)[1]' `dspmq`
There's also -M to load modules (e.g. -MData::Dumper), but you don't seem to be using Data::Dumper any more.

Answer 2

split isn't going to do what you need. I would just use a regular expression to match the sub-string you need
So change the loop from this
foreach my $i (#qmgrlist)
{
my #temp1 = split /QMNAME\(/, $i;
print #temp1;
}
to this
foreach my $i (#qmgrlist)
{
print "$1\n"
if /QMNAME\((.+?)\)/;
}

Answer 3

Try this perl one-liner:
dspmq | perl -lne 'print for m{ QMNAME [(] ( [^)]* ) [)] }x'
Here, dspmq STDOUT is fed using a pipe | into STDIN of the perl code, which has these flags:
-e tells Perl interpreter to look for the code inline rather than in a separate script file.
-n feeds the input line by line to the inline code (this way you do not need to store the output in an array - this matters for large outputs, not in your case).
-l strips the input record separator (newline on *NIX) before feeding it to the code, and appends it automatically after during print.
The print ... for ... m{... (...) ...} code prints every pattern captured in parentheses.
The captured pattern is [^)]*, which is maximum number (0 or more) chars that are not (^) listed in the character class, that is, that are not closing parens.
[(] ... [)] are literal parentheses escaped as character classes for readability. I prefer this to escaping like so: \( ... \).
QMNAME is used to make the programmer's intentions clear: you want the string that follows QMNAME in parens. I prefer this to using the field index, such as 1, which protects you against minor variation in output of your command used with different options, on different systems, etc.
Finally, the x regex modifier in m{...}x enables comments and whitespace to be ignored, and is preferred for readability.
RELATED:
Cutting the output of a dspmq command

Answer 4

Desired output can be achieved with following code
use strict;
use warnings;
use feature 'say';
map{ say $1 if /QMNAME\((.+?)\)/ } <DATA>;
__DATA__
QMNAME(AAA) STATUS(Running)
QMNAME(BBB) STATUS(Running)
output
AAA
BBB
and one liner (not tested - I am on Windows computer)
dspmq | perl -lne 'print $1 if /QMNAME\((.+?)\)/'