If you know the start and end point use a range operator.

Note: In this context "eof" doesn't really correspond to the eof end-of-file marker, it is just a string that isn't found before the end of the file. It works in this situation, but beware of using it in a general case. If you want the true eof marker, use the hex char at ordinal 4, "\x4"

use warnings;
use strict;

my $start = '4-Dec-2009';
my $end   = "eof";

print "Date,Total\n";

while (<DATA>) {
    if ( /^$start/ .. /^$end/ ) {
        chomp;
        my (@items) = split /,/;
        printf "%s,%d\n", $items[0], $items[1] + $items[2];
    }
}

__DATA__
Date,Expense,Income
1-Dec-2009,12,87
2-Dec-2009,54,204
3-Dec-2009,75,214
4-Dec-2009,78,198
5-Dec-2009,98,155
6-Dec-2009,10,180
7-Dec-2009,51,91
8-Dec-2009,32,130
9-Dec-2009,29,207

[download]

produces:

Date,Total
4-Dec-2009,276
5-Dec-2009,253
6-Dec-2009,190
7-Dec-2009,142
8-Dec-2009,162
9-Dec-2009,236

[download]

In reply to Re: copying records from one file to another with filter. by thundergnat
in thread copying records from one file to another with filter. by avanta

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