Help with a perl problem

[negzero7]

Hi everyone,

I am trying to teach myself Perl with the aid of some books I have boughten. I'm doing some exercises with regular expressions but am having some trouble, specifically with this problem:

Write a program that prints only words (not the entire line) in the file part3.txt (attached) on a word boundary that have the letter "p" or "P" in them.

The Unix command line should look like:

$ proj2_3.pl part3.txt

The output should look like:

Perl
pattern
pattern
Perl
help

The text file given is this:

CPAN stands for comprehensive Perl Archive Network.
^ and $ are used as anchors in a regular expression.
/pattern/ is a pattern match operator.
Perl is very easy to learn.
Enter 'H' or 'h' for help.

So far what I have is this:

#!usr/bin/env perl
 
open  (test, "@ARGV");
 
while (<test>) {    
    m/p/gi;
    print;
}
 
close (test);

Someone please lend a helping hand :)

[negzero7]

/bump

No one has any idea about this? Is there some regular expression that can find a character and print out the word it's in?

[KevinADC]

The obvious way is to use the split() function and split the lines into words then check each word for /[Pp]/ instead of each line, like you are doing. But I have no idea what the book you are reading has covered so far so making specific suggestions may not be relevant to where you are in the lessons/book.

Kevin(R) ;)

[eWish]

Check out perlre and perlrequick. Look for "Match a word boundary"

--Kevin

[nithinpes]

You should also look out for '/' or '.' occuring near word boundaries. The following script will do the job.

#!usr/bin/env perl
while (<>) {    
         while(/\b[.\/]?(\w+)[.\/]?\b/g) {
             $word = $1;
             print "$word\n" if($word=~/^p|p$/i);
       }
}
 

But, inorder to understand this regex better or to extend this for some other scenario, kindly go through the links posted by Kevin.