my %h = map { ( split /=/, $_, 2 ) } split /,/;
to
my %h = map { ( split /=/, $_, 1 ) } split /,/;
and
my %h = map { ( split /=/, $_, 3 ) } split /,/;

print "$h{'msgagt'}\n" if exists $h{'msgagt'};

##</code><code>##

ESM_WMB_AIX
Odd number of elements in hash assignment at parse_4_ovo.plx line 20, <$out> line 3.
Odd number of elements in hash assignment at parse_4_ovo.plx line 20, <$out> line 7.
Odd number of elements in hash assignment at parse_4_ovo.plx line 20, <$out> line 9.
Odd number of elements in hash assignment at parse_4_ovo.plx line 20, <$out> line 11.