use strict;
my $str = 'May 29 14:51:56 deast01pano.xxxxx.com 1,2018/05/29 14:51:56,012501001022,6553964590112973819,0x8000000000000000,USERID,login,2049,2018/05/29 14:51:50,0,0,0,0,vsys1,dwest01fw,1,vsys1,10.142.10.172,xxxxx\\pulse,deast01fwua.xxxxx.com,0,1,2700,0,0,agent,,0,0,,2018/05/29 14:51:47,1,0,0,0x0,xxxxx\\pulse';
my $regex = qr/USERID,(?:[^,]+,){8}(\w+)/mp;
if ( $str =~ /$regex/g ) {
print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n";
# print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n";
# print "Capture Group 2 is $2 ... and so on\n";
}
# ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p'
# Named capture groups can be called via $+{name}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html