#!/usr/bin/perl

use strict;
use warnings;

my $start_target_name = "";

for (<DATA>) {
## line to process?
      if (/^>probe:/)
      {
## first record processing
         ($start_target_name) = /.*:(\d\d\d+_at:).*/ if ($start_target_name eq "");
## Got new target? or got not last target?
         if (!/.*:$start_target_name.*/)
         {
            print " do neat stuff for prior target $start_target_name\n";
## set up for next target
            ($start_target_name) = /.*:(\d\d\d+_at:).*/;
         }
      }
}
## process last set
print " do neat stuff for prior target $start_target_name\n";

__DATA__
>probe:MOE430A:1415670_at:549:177; Interrogation_Position=2436; Antise nse;
GGCTGATCACATCCAAAAAGTCATG
>probe:MOE430A:1415670_at:549:177; Interrogation_Position=2513; Antise nse;
GAGGAAACGTTCACCCTGTCTACTA
>probe:MOE430A:1415670_at:467:433; Interrogation_Position=2521; Antise nse;
GTTCACCCTGTCTACTATCAAGACA
>probe:MOE430A:1415670_at:254:643; Interrogation_Position=2533; Antise nse;
TACTATCAAGACACTCGAAGAGGCT
>probe:MOE430A:1415670_at:54:269; Interrogation_Position=2556; Antisen se;
CTGTGGGCAATATTGTGAAGTTCCT
>probe:MOE430A:1415670_at:405:339; Interrogation_Position=2583; Antise nse;
GAATGCATCCTTGTGAGAGGTCAGA
>probe:MOE430A:1415670_at:60:395; Interrogation_Position=2597; Antisen se;
GAGAGGTCAGACAAAGTGCCAGAAA
>probe:MOE430A:1415670_at:284:165; Interrogation_Position=2619; Antise nse;
AAAACAAGAACACCCACACGCTGCT
>probe:MOE430A:1415670_at:622:145; Interrogation_Position=2634; Antise nse;
ACACGCTGCTGCTAGCTGGAGTATT
>probe:MOE430A:1415670_at:291:661; Interrogation_Position=2804; Antise nse;
TATCTTGTCCAACACTACGTCGAAG
>probe:MOE430A:1415670_at:146:701; Interrogation_Position=2956; Antise nse;
TTGTCACCATGCCTGCAAGGAGAGA
>probe:MOE430A:1415671_at:116:525; Interrogation_Position=1156; Antise nse;
GGAACAGGAATGTCGCAACATCGTA
>probe:MOE430A:1415671_at:655:137; Interrogation_Position=1173; Antise nse;
ACATCGTATGGATTGCTGAGTGCAT
>probe:MOE430A:1415671_at:398:139; Interrogation_Position=1232; Antise nse;