Pattern matching in file and then display 10 lines above every time - Page 2

KevinADC · #1 (**permalink**) 10-20-2008

After 9 months the thread is a bit stale but maybe your post will still be helpful.

sethcoop · #2 (**permalink**) 10-20-2008

What about a simple little perl script????.... the 10 lines above the word "total" will be printed... it will read a file called file.txt.

Code:

#!/usr/local/bin/perl
@array;
open(F, "file.txt") or die "cannot read file";
while(<F>) {
  chomp;
  $my_line = "$_";
 
  if ("$my_line" =~ "total") {
    foreach(@array){
      print "$_\n";
    }
    print "========================================================\n"
  }
  push(@array,$my_line);
  if ("$#array" > "9") {
    shift(@array);
  }
};

digitalrg · #3 (**permalink**) 04-08-2009

Thank you sethcoop.. but can you please tell me how to print 10 lines below the occurance of word "total" please help.....
Thanks

Quote:

Originally Posted by sethcoop

What about a simple little perl script????.... the 10 lines above the word "total" will be printed... it will read a file called file.txt.

Code:

#!/usr/local/bin/perl
@array;
open(F, "file.txt") or die "cannot read file";
while(<F>) {
  chomp;
  $my_line = "$_";
 
  if ("$my_line" =~ "total") {
    foreach(@array){
      print "$_\n";
    }
    print "========================================================\n"
  }
  push(@array,$my_line);
  if ("$#array" > "9") {
    shift(@array);
  }
};

sethcoop · #4 (**permalink**) 04-08-2009

Quote:

Originally Posted by digitalrg

Thank you sethcoop.. but can you please tell me how to print 10 lines below the occurance of word "total" please help.....
Thanks

Here is the code to print the number of lines below your search... you can change the variable $lines to be how many lines you want to print after the word total.

Hope this helps!

Code:

#!/usr/bin/perl
$lines = 10;
$x = $lines;
open(F, "file.txt") or die "cannot read file";
while(<F>) {
  chomp;
  $my_line = "$_";
  if ("$x" < "$lines") {
    print "$my_line\n";
    $x++;
  }
  if ("$my_line" =~ "total") {
    $x = 0;
  }
};

KevinADC · #5 (**permalink**) 04-08-2009

Quote:

Originally Posted by digitalrg

Thank you sethcoop.. but can you please tell me how to print 10 lines below the occurance of word "total" please help.....
Thanks

I know sethcoop is trying to help but his perl code is not well written, here is what you want to do:

Code:

#!/usr/bin/perl
use strict;
use warnings;
my $lines = 10;
open(F, "file.txt") or die "cannot read file";
while(<F>) {
  if (/total/)  {
      print scalar <F> for (1..$lines);
      last;
  }
}
close(F);

Couple of things. If you need to find "total" more than once, remove the "last" command" otherwise it quits after the first match. If "total" is not a substring of another word add the \b anchor to the regexp so you don't get any false substring matches for words like "totals" instead of just "total".

Code:

if (/\btotal\b/)  {

add "i" to the regexp to make it case-insensitive if necessary so "TOTAL" and "total" will match:

Code:

if (/\btotal\b/i)  {

ghostdog74 · #6 (**permalink**) 04-10-2009

Quote:

Originally Posted by KevinADC

I know sethcoop is trying to help but his perl code is not well written, here is what you want to do:

Code:

#!/usr/bin/perl
use strict;
use warnings;
my $lines = 10;
open(F, "file.txt") or die "cannot read file";
while(<F>) {
  if (/total/)  {
      print scalar <F> for (1..$lines);
      last;
  }
}
close(F);

borrowed from awk

Code:

line: while (<>) {
    if (/line 5/){ $c = 5; next line; }
    print $_ if $c-- >0 ;
}

Franklin52 · #7 (**permalink**) 04-08-2009

Quote:

Originally Posted by digitalrg

.. but can you please tell me how to print 10 lines below the occurance of word "total" please help.....
Thanks

With awk:

Code:

awk '/total/{c=10;next}c-->0' file

Regards

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