use strict; use warnings; use feature qw{ say }; my %replacementLU = ( QOS_PROFILE_ID => q{x1}, CHARGING_PROFILE_ID => q{x2}, CONTENT_FILTERING_PROFILE_ID => q{x3}, SUBSCRIBERID => q{x4}, RECORD_LENGTH => q{x5}, RECORD_TYPE => q{x6}, EVENT_ID => q{x7}, EVENT_RESULT => q{x8}, CAUSE_PROTOCOL => q{x9}, DEFAULT_BEARER_ID => q{x0}, ARP_PRIORITY_LEVEL => q{y1}, ARP_CAPABILITY => q{y2}, ARP_VULNERABILITY => q{y3}, BEARER_CONTROL_MODE => q{y4}, TRACKING_AREA_CODE => q{y5}, ROUTING_AREA_CODE => q{y7}, SERVICE_AREA_CODE => q{y8}, SYSTEM_IDENTIFIER => q{y9}, NETWORK_IDENTIFIER => q{y0}, GX_RAR_RAA_TRANSACTION => q{TRAR}, GX_CCR_CCA_TRANSACTION => q{TCCA}, QUOTA_GRANTED => q{TQG}, QOS_ASSIGNED_TO_DEFAULT_BEARER => q{TQA}, RULE_INSTALLED => q{TRI}, RULE_REMOVED => q{TRR}, ); my $subsRE = do { local $" = q{|}; qr{(?x) \b ( @{ [ keys %replacementLU ] } ) \b}; }; my $text = q{blurfl,ARP_VULNERABILITY,17,blargle,EVENT_ID,4,glogl}; say $text; $text =~ s{$subsRE}{$replacementLU{ $1 }}g; say $text; #### blurfl,ARP_VULNERABILITY,17,blargle,EVENT_ID,4,glogl blurfl,y3,17,blargle,x7,4,glogl