UNIX for Dummies Questions & Answers

#! /opt/third-party/bin/perl

my ($content, $i, $header, $headerprint, %fileHash);
open(FILE, "< a") || die "Unable to open file : $!\n";

while( chomp($content = <FILE>) ) {
  if( $content =~ m/^H/ ) {
    foreach $att (@disp) {
      if( $headerprint == 0 ) {
        $headerprint = 1;
        print "$header\n";
      }
      print "$att\n";
    }
    $headerprint = 0;
    $header = $content;
    %fileHash = ();
    @disp = ();
  }
  else {
      push(@disp, $content) if exists $fileHash{$content};
      $fileHash{$content} = $i++;
  }
}
foreach $att (@disp) {
  if( $headerprint == 0 ) {
    $headerprint = 1;
    print "$header\n";
  }
  print "$att\n";
}

close(FILE);
exit 0

$ awk '/^H/{h=$0;f=0}$0==p{print (f?"":h ORS) p;f=1}{p=$0}' file1 
HA
D2
D4
HC
D1
D3

#!/usr/bin/python
import sys,os
filename = sys.argv[1]
headers = {"HA": [] , "HB": [], "HC": []}
for line in open(filename):
    line = line.strip() #strip new line
    if headers.has_key(line):
        flag = 1
        k = line
    elif flag:
        headers[k].append(line)
print "File %s:" % filename
for key in sorted( headers.keys() ):
    for s in set( headers[key] ):
        if headers[key].count(s) > 1:
            print key
            print '\n'.join( set(headers[key] )  )
            break