New Lines in an Output File

[beginnerperl]

Hello All,
I am writing a perl program that pars through a text file and find a particular word and reverse the word. I can do that fine, but when creating the output file, the output files gives me that text file in one line. I want the progream to insert a new line anytime it sees the new line in the text file.
for example, my text file looks like this.

1-database one was in here. where have you been these day.
2- I am not sure what do to with eht database.
3- perl is a good for parsing eht database data.
 

but the output gives me:
1-database one was in here. where have you been these day.2- I am not sure what do to with eht database.3- perl is a good for parsing eht database data.


The program is.

#!/usr/bin/perl
 
open (FH, "text");
open (out, ">", "out3");
 
while (<FH>) {
    # chomp;
    @ar = split (' ', $_);
    for ($i=0; $i < @ar; $i++){
        if ((@ar[$i] eq 'Database.') || (@ar[$i] eq 'Database')) {
            $arr = @ar[$i];
            $arrr = reverse ($arr);
            @ar[$i] = $arrr;
        } else {
 
        }
        print out "@ar[$i] ";
    }
}
 

thanks in advance for the help.

[miller]

Hi beg,

Just add a print return line after your for loop:

    print out "\n";
}
 

- Miller

PS, there are lots of ways that your code could and probably should be improved. Namely the use of "array slices" is a bad habit to get into. And not declaring any of your variables with my is also unwise. Nevertheless, I leave this to you to discover in time.

[miller]

An expert method for doing what you described:

#!/usr/bin/perl
 
open(IN, "text") or die "Can't open text: $!";
open(OUT, "> out3") or die "Can't open out3: $!";
 
while (<IN>) {
    s/(Database\.?)/reverse $1/eig;
    print OUT;
}
 
close IN;
close OUT;
 

[beginnerperl]

Hi Miller,
Thanks for your reply. I have used your code and it works the way I want it. But I just started to learn perl and wanted to use Array and manipulate the array content. The only problem I am having, how to detect a new line in my array and insert it in the outpurt file. for example, here my TEXT file that I am using and parsing:


Fhaw was in here
Deda was Database.
here we go
there we go


Database. j1-king senior technologists.
Database. across HP is an important step in strenghening our technology communit
y. To that end, I am pleased to announce the new technical Caree Path (TCP) Mas
ters
0- Database.
1- Database.
2- Database
3- Database
4- Database

And here is the output of my prgramm after I ran my program:

Fhaw was in here Deda was esabataD in here here we go there we go
test text. .esabataD j1-king senior technologists. .esabataD across HP
is an important step in strenghening our technology community. To th
at end, I am pleased to announce the new technical Caree Path (TCP)
Masters 0- .esabataD 1- .esabataD 2- esabataD 3- esabataD 4- esabataD.



I ran your code and it gave me what I want, but I need my program to gives me the same output that your code gave me.


By the way, here is what your code gave me after running it which is what I want


Fhaw was in here
Deda was esabataD in here
here we go there we go
test text.
.esabataD j1-king senior technologists.
.esabataD across HP
is an important step in strenghening our technology community. To th
at end, I am pleased to announce the new technical Caree Path (TCP)
Masters
0- .esabataD
1- .esabataD
2- esabataD
3- esabataD
4- esabataD

[beginnerperl]

By the way,
Can you explain your code:

s/(Database\.?)/reverse $1/eig;

Please?

Thanks

[miller]

You can read about regular expressions here:

http://perldoc.perl.org/perlrequick.html

As for attempting your problem in a more verbose method. Here:

#!/usr/bin/perl
 
use strict;
 
open(IN, "text") or die "Can't open text: $!";
open(OUT, "> out3") or die "Can't open out3: $!";
 
while (<FH>) {
    chomp;
    my @array = split ' ', $_;
    for (my $i=0; $i<@array; $i++){
        if (($array[$i] eq 'Database.') || ($array[$i] eq 'Database')) {
            $array[$i] = reverse $array[$i];
        }
    }
    print OUT join(' ', @array) . "\n";
}
 
close IN;
close OUT;
 

As is almost always the case with perl, there are many different ways to make the above code more efficient in both a performance and a lines required sort of way. Nevertheless, this maybe will enlighten you concerning the problems you were having.

- Miller