Shell Programming and Scripting

awk 'FNR==NR{print "File processing now: " FILENAME "  FNR: "FNR " NR: "NR ;print $0;next}
     { print "File processing now: " FILENAME " NR: " NR " FNR:  " FNR " : "$0 }
' "file1" "file2"

awk 'BEGIN{flag=0}
{
if ($2=="XXX")
{
	print
	flag=1
}
if ($1=="**" && $2!="XXX")
	flag=0
if (flag==1 && $2=="k=")
	print
}' filename

#!/usr/bin/perl

# @(#) p3       Demonstrate extraction after pattern match.

use warnings;
use strict;

my ($debug);
$debug = 1;
$debug = 0;

our ($lines) = 0;
my ($key_string);

my (@a);

# Get second field of first line that begins with **, as in:
#
# ** XXX
#
# then use that second field as the key_string. Anytime that
# key_string appears, we begin scanning for "k=" lines, and only
# stopping when another "**" line appears.
#
# So, read until ** XXX, then turn over control to function to
# scan for other pattern.

my ($first) = 1;
while (<>) {
  if ($first) {
    @a = split;
    if ( $a[0] eq "**" ) {
      $key_string = $a[1];
      $first      = 0;
      redo;
    }
  }
  $lines++;
  chomp;
  @a = split;
  if ( $a[0] eq "**" && $a[1] eq $key_string ) {
    print " Found XXX line at $.\n" if $debug;
    print "$_\n";

    # last if not extract_k();
    $_ = extract_k();
    if ( not $_ ) {
      last;
    }
    else {
      print " cycling with line $. ", $_ if $debug;

      # Adjust line count to avoid counting twice.
      $lines--;
      redo;
    }
  }
}

print STDERR " ( Lines read: $lines )\n";

# Extract k= lines until line with "**".

sub extract_k {
  our ($lines);
  my (@a);
  while (<>) {
    $lines++;
    chomp();
    @a = split;
    return "$_\n" if $a[0] eq "**";    # not EOF
    print "$_\n" if /k=/;
  }
  return 0;                            # EOF
}

exit(0);

% ./p3 data3
** XXX ccc ccc cc cc ccc 2007
0001 k= 1
0002 k= 1
** XXX ccc ccc cc cc ccc 2007
0003 k= 1
0004 k= 1
0005 k= 1
 ( Lines read: 29 )