When I compile that with warnings and strict enabled I get these messages:

main::dumpHistory() called too early to check prototype at 755780.pl.t
+dy line 87.
main::dumpHistory() called too early to check prototype at 755780.pl.t
+dy line 74.
main::dumpHistory() called too early to check prototype at 755780.pl.t
+dy line 63.
main::dumpHistory() called too early to check prototype at 755780.pl.t
+dy line 53.
Global symbol "@results" requires explicit package name at 755780.pl.t
+dy line 27.
Global symbol "$item" requires explicit package name at 755780.pl.tdy 
+line 30.
Global symbol "@results" requires explicit package name at 755780.pl.t
+dy line 30.
Global symbol "$item" requires explicit package name at 755780.pl.tdy 
+line 31.
Global symbol "$item" requires explicit package name at 755780.pl.tdy 
+line 33.
Global symbol "$item" requires explicit package name at 755780.pl.tdy 
+line 40.
Global symbol "$item" requires explicit package name at 755780.pl.tdy 
+line 42.
Global symbol "$clientName" requires explicit package name at 755780.p
+l.tdy line 44.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 46.
Global symbol "$clientName" requires explicit package name at 755780.p
+l.tdy line 46.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 48.
Global symbol "$clientName" requires explicit package name at 755780.p
+l.tdy line 56.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 58.
Global symbol "$clientName" requires explicit package name at 755780.p
+l.tdy line 58.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 59.
Global symbol "$clientName" requires explicit package name at 755780.p
+l.tdy line 66.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 68.
Global symbol "$clientName" requires explicit package name at 755780.p
+l.tdy line 68.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 70.
Global symbol "$clientName" requires explicit package name at 755780.p
+l.tdy line 77.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 79.
Global symbol "$clientName" requires explicit package name at 755780.p
+l.tdy line 79.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 81.
Global symbol "$item" requires explicit package name at 755780.pl.tdy 
+line 94.
Global symbol "@history" requires explicit package name at 755780.pl.t
+dy line 94.
Global symbol "$item" requires explicit package name at 755780.pl.tdy 
+line 95.
Global symbol "$item" requires explicit package name at 755780.pl.tdy 
+line 96.
Bareword "NULL" not allowed while "strict subs" in use at 755780.pl.td
+y line 48.
Bareword "NULL" not allowed while "strict subs" in use at 755780.pl.td
+y line 59.
Bareword "NULL" not allowed while "strict subs" in use at 755780.pl.td
+y line 70.
Bareword "NULL" not allowed while "strict subs" in use at 755780.pl.td
+y line 81.
[download]

Perhaps it would work better like this:

use warnings;
use strict;
##
## Sherlock v0.1 written 040409:1650 by BJP
##
## Sherlock, given a hostname, can determine if that host is known to 
+netbackup.
##
## Usage:  sherlock.pl <hostname>
##


if ( @ARGV != 1) {
    print "\n\nUsage:  sherlock.pl <hostname>\n";
    print "Example: sherlock.pl cistest\n\n";
    exit 1;
    }

print "\nSherlock: Starting up..\n";

if ( $ARGV[ 0 ] =~ s/^b_// ) {
    print "Sherlock: Stripping off the \"b_\" prefix temporarily..\n";
    }

print "Sherlock: Checking to see if NetBackup knows about $ARGV[0]..\n
+";

my @results = `/usr/openv/netbackup/bin/bpclntcmd -pn -hn $ARGV[0] 2>&
+1 `;    ## For some reason, this command will dump ordinary status in
+formation to stderr versus stdout, hence the gag suffix on the comman
+d.


for my $item ( @results ) {
    chomp $item;

    if ( $item =~ /TRY_AGAIN/ ) {
        print "Sherlock: Bad news. NetBackup does not recognize $ARGV[
+0] as a valid peer name under its care.\n";
        print "Sherlock: Test results: FAIL\n";
        print "Sherlock: Exiting..\n\n";
        exit 2;
        }

    next if $item !~ /0x/;
    print
        "Sherlock: Good news! NetBackup recognizes $ARGV[0] as a valid
+ client and peer name.\n",
        "Sherlock: Details: $item\n";

    my $clientName = $ARGV[ 0 ];

    my @history = `/usr/openv/netbackup/bin/bpclimagelist -t ANY -clie
+nt $clientName`;
    dumpHistory( @history ) if @history;

    print
        "Sherlock: A check of the backup logs for this client shows no
+thing so far.. Still searching..\n",
        "Sherlock: This time, let's try again using a \"b_\" prefix on
+ the hostname and see what happens..\n";

    $clientName = "b_$ARGV[0]";

    @history = `/usr/openv/netbackup/bin/bpclimagelist -t ANY -client 
+$clientName`;
    dumpHistory( @history ) if @history;
    print "Sherlock: I'm still not seeing anything for this host. Hmmm
+.. Maybe it's a Wintel box? Lets try that..\n";

    $clientName = $ARGV[ 0 ];

    @history = `/usr/openv/netbackup/bin/bpclimagelist -t ANY -client 
+$clientName -ct 5`;
    dumpHistory( @history ) if @history;
    print "Sherlock: No luck.. I'm not seeing anything on it. Trying a
+gain, assuming it's a Wintel box AND \"b_\" prefixed..\n";

    $clientName = "b_$ARGV[0]";

    @history = `/usr/openv/netbackup/bin/bpclimagelist -t ANY -client 
+$clientName -ct 5`;
    dumpHistory( @history ) if @history;
    print
        "Sherlock: Still no luck. This box needs to be checked manuall
+y.\n",
        "Sherlock: Test results: FAIL\n",
        "Sherlock: Exiting..\n\n";
    }

sub dumpHistory {
    print "Sherlock: Ahhh, there we go. Results! This host appears to 
+have a backup history..\n";
    for my $item ( @_ ) {
        chomp $item;
        print "Sherlock: $item\n";
        }

    print
        "Sherlock: Test results: PASSED\n",
        "Sherlock: Exiting..\n\n";
    exit;
    }
[download]