On Aug 21, 4:33 am, xecro...@yahoo.com (Ron Weidner) wrote:
> Recently, I was asked to find the first occurrence of a word in a text file
> and replace it with an alternate word. This was my solution. As a new Perl
> programmer, I feel like this solution was too C like and not enough Perl
> like. So, my question is what would have been the Perl like solution to this
> problem?
>
> In this example there is little risk of running out of memory reading the
> file. But had this been a production environment or an unknown file size, I
> would have had to consider that.
>
> #!/usr/bin/perl
> use strict;
> use warnings;
>
> #program finds the first occurrence of the word Dood and
> #replaces it with the word Dude in the file data.txt.
>
> open FP, "+<", "data.txt" || die "Cant open data.txt " . $!;
>
> my @buffer = <FP>;
> seek FP,0,0;
> my $do_replace = 1; #used to control replacing in multiline files.
> my $line;
> my $data;
> foreach $data (@buffer)
> {
> if ($do_replace == 1)
> {
> $line = $data;
> $data =~ s/Dood/Dude/;
> if ($line ne $data)
> {
> $do_replace = 0; #we did a substitution so do no more.
> }
> }
> print FP $data;}
>
> close FP;
>
> #Test data
> #Dude! Where's my car?
> #Dood! Where's my car?
> #Dood! Where's my car?
>
>
If you're permitted a one-liner:
perl -pi.bak -e '$c=s/Dood\/Dude/ if !$c++' file
--
Charles DeRykus
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