Hello, adapting your code:
#!/usr/bin/perl
use strict;
use warnings;
my $previous_line = <DATA>;
while ( my $current_line = <DATA> ) {
chomp for ( $previous_line, $current_line );
my @previous_cols = split ' ', $previous_line;
my @current_cols = split ' ', $current_line;
print "$current_cols[0]: $current_cols[1] ";
$current_cols[1] += $previous_cols[1];
print "now changed to $current_cols[1]\n";
$previous_line = join ' ', @current_cols;
}
__DATA__
seed 1
foo 1
bar 2
baz 3
qux 4
Output:
foo: 1 now changed to 2
bar: 2 now changed to 4
baz: 3 now changed to 7
qux: 4 now changed to 11
You may want to look at Text::CSV_XS for this kind of task.
Hope this helps!
The way forward always starts with a minimal test.
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|