Re^3: Extracting data from a particular line to end of the file

The simple implementation of this is like below. Keep a record of whether the "start" has happened yet. And if it has, then print all the lines after that and including that one.

code example and output.. click below..

#!/usr/bin/perl -w
use strict;

my $seen_once =0;
while (<DATA>)
{
   $seen_once =1 if (m/^\*/);
   print if $seen_once;
}
=prints:
the line "Gain... " IS NOT PRINTED

*Check if your claims have been finalized.
*Sign up for alerts about your claim activity.
*Print a temporary ID card.
*View up to 18 months of claim payment details.
*Much, much more!
In addition you, your spouse and children can:
*Search for Doctors and Hospitals in your area.
*Begin a program to stop smoking or lose weight.
*Learn more about a specific disease or condition". 
=cut

__DATA__
"Gain immediate access and...
*Check if your claims have been finalized.
*Sign up for alerts about your claim activity.
*Print a temporary ID card.
*View up to 18 months of claim payment details.
*Much, much more!
In addition you, your spouse and children can:
*Search for Doctors and Hospitals in your area.
*Begin a program to stop smoking or lose weight.
*Learn more about a specific disease or condition".
[download]

More specific version of your code:

open (my $file1,"<$dir/seq.results") or die "cannot open "$dir/seq.res
+ults";
open (my $file2,">$dir/seq.out") or die "cannot open $dir/seq.out" for
+ write";

my $started =0;
while (<$file1>)
{
   $started =1 if (m/^\*/); #first line starting with * is seen
   print $file2 "$_" if $started;
}
[download]

Note: '*' has special meaning within a regex and it has to be "escaped" to get the literal value of '*'.

Yes, there are ways of coding this in a more brief way. But do not confuse brevity with execution efficiency and certainly not clarity.

Oh, in a very simple program like this (6 lines), there is no need to explicitly close the file handles ($file1 and $file2). The OS will do that for you when the program exits. In longer programs there can be good reasons to do that.

Comment on Re^3: Extracting data from a particular line to end of the file Select or Download Code

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Re^4: Extracting data from a particular line to end of the file by manne (Novice) on Dec 21, 2010 at 18:18 UTC
Thankyou marshall, That was really helpful...	[reply]