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Full Discussion: Perl: Conditional replace based on previous and current value in a line
Top Forums Shell Programming and Scripting Perl: Conditional replace based on previous and current value in a line Post 302602527 by birei on Monday 27th of February 2012 03:50:20 PM
Old 02-27-2012
Hi naveen@,

I don't understand your perl script. It outputs nothing with that input file, and I think you didin't match the exact withespace.

Try next one:
Code:
$ cat infile
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = P0; /* if next shift_port is P0 I need to replace this with M0; and next shift_port's P0; with 00;
    port3       = 0;
    reset       = 1;
   }
  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = P0;
    port3       = 0;
    reset       = 1;
   }
  Macro "Inputs" { 
    test_ip =
        110111010110
  }

  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = 00;
    port3       = 0;
    reset       = 1;
  }
  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = 00; 
    port3       = 0;
    reset       = 1;
   }
  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = P0;/* if next shift_port is P0; I need to replace this with M0; and next shift_port's P0 with 00;
    port3       = 0;
    reset       = 1;
   }
  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = P0;/* if next shift_port is P0; I need to replace this with M0; and next shift_port's P0 with 00;
    port3       = 0;
    reset       = 1;
   }
}
$ cat script.pl
use warnings;
use strict;

die qq[Usage: perl $0 <input-file>\n] unless @ARGV == 1;

my @range_lines = ();

while ( <> ) {
        chomp;
        if ( m/\A\s*(?i:shift_port)\s*=/ ... m/\A\s*(?i:shift_port)\s*=/ ) {
                push @range_lines, $_;
                next;
        }

        if ( @range_lines ) {
                if ( $range_lines[0] =~ m/=\s*P0\s*;/ &&
                         $range_lines[ $#range_lines ] =~ m//
                ) {
                        $range_lines[0] =~ s/P0/M0/;
                        $range_lines[ $#range_lines ] =~ s/P0/00/;
                }

                printf qq[%s\n], join qq[\n], splice @range_lines;
        }

        printf qq[%s\n], $_;
}
$ perl script.pl infile
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = M0; /* if next shift_port is P0 I need to replace this with M0; and next shift_port's P0; with 00;
    port3       = 0;
    reset       = 1;
   }
  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = 00;
    port3       = 0;
    reset       = 1;
   }
  Macro "Inputs" { 
    test_ip =
        110111010110
  }

  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = 00;
    port3       = 0;
    reset       = 1;
  }
  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = 00; 
    port3       = 0;
    reset       = 1;
   }
  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = M0;/* if next shift_port is P0; I need to replace this with M0; and next shift_port's P0 with 00;
    port3       = 0;
    reset       = 1;
   }
  W wf_cyc;
  V { 
    port1       = P;
    port2       = 0;
    shift_port  = 00;/* if next shift_port is P0; I need to replace this with M0; and next shift_port's P0 with 00;
    port3       = 0;
    reset       = 1;
   }
}

Regards,
Birei
This User Gave Thanks to birei For This Post:
naveen@
 

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LEARN ABOUT DEBIAN

cutter

CUTTER(8)						      System Manager's Manual							 CUTTER(8)

NAME

       cutter - cut tcp/ip connections

SYNOPSIS

       cutter ipaddress1 [ port1 [ ipaddress2 [ port2  ]  ]  ]

DESCRIPTION

       Cutter  is  an open source program that allows Linux firewall administrators to abort TCP/IP connections routed over the firewall or router
       on which it is run.

WARNING

       Cutter has been designed for use as a administrators tool for Linux firewalls. It's use (as is, or modified) for any other purpose  is  not
       sanctioned by the author. So - do not use this tool as a parachute, or to dry your cat, chill meat, answer your phone, drive you car, teach
       your kids to read or attack other people's computer systems or networks.

       This software has been designed for legal and appropriate use by network security administrators and the like. It has been written as  part
       of  a  larger Linux firewall project, targetting at controlling traffic from peer-to-peer software such as Kazaa, iMesh and others into and
       out of a private network. It is not designed as a tool for malicious use and the author in no way sanctions such use.

       Users of the software should be aware that it's actions are easily detectable using a number of readily available network monitoring tools,
       and it makes no attempt to disguise it's actions. Malicious use of "cutter" could result in a jail sentance in a number of countries around
       the world.

       The author is not responsible for the results of using this software. It is provided "as is" in the hope that it will  be  useful,  but	no
       garantees are made about it's use.

USAGE

       Cutter can be called using one of the following four syntaxes.

       cutter ip-address

       Example:
	      cutter 10.10.0.45

	      Cuts  all  connections  passing  through	the firewall between any ports on the specified ip-address (either a "private" or "public"
	      address) and any other hosts. This can be used to close down all incoming connections to a particular server, all  outgoing  connec-
	      tions from a particular client or all outgoing connections to a server.

       cutter ip-address port

       Example:
	      cutter 200.1.2.3 80

	      Cuts  all connections to or from the specified ip-address/port pair. This allows the user to be a little more specific than the pre-
	      vious example and allows targetting of specific services on specific hosts.

       cutter ip-address-1 port-1 ip-address-2

       Example:
	      cutter 200.1.2.3 22 10.10.0.45

	      Cuts all connections between ip-address-2 and ip-address-1/port-1. This allows the user  to  cut	connections  between  a  specified
	      "client" and a particular service on a specified host. Our example closes host 10.10.0.45's SSH connection to server 200.1.2.3.

       cutter ip-address-1 port-1 ip-address-2 port-2

       Example:
	      cutter 200.1.2.3 22 10.10.0.45 32451

	      Cuts the specific connection between the two ip/port number pairs given.

STATUS

       Cutter  1.03  should  be considered EXPERIMENTAL.  The author is releasing a tool that works on the systems he has access to (namely: IPCop
       and RedHat Linux), and he is seeking input on it's use on other systems, ideas for improvement, offers of sponsorship - etc.

ADDITIONAL DOCUMENTATION

       This program is documented at http://www.lowth.com/cutter/ <http://www.lowth.com/cutter/>

AUTHOR

       Blars Blarson addapted the README and web page written by Chris Lowth into this man page for debian package of cutter.  This man  page  may
       be distribuated under the terms of the Gnu GPL version 2.

								    April, 2005 							 CUTTER(8)
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