It's also something I could see someone doing self-study in perl might choose as a sample problem to solve themselves.

Either way, my answer is going to be the same: Read the documentation.

Specifically, you'll probably want to open a file for reading and/or writing (check the perl docs for the "open" function), use a while loop to read each line in the file one by one (check the docs for the "while" statement), find the length of the line read (can you guess the function name to find the length of a string?), and possibly look up how to print stuff to a file.

It's sort of cheating to do system("wc -lc $infile > $outfile"); in my opinion.

It sounds like to me that you haven't tried any of the things in the Perl book that might answer this question. You do have a Perl book, don't you? I can highly recommend the fine series of books from O'Reilly.

In any event, the variable $. tells you what line you're on, so printing that out after reading through the file would tell you what number the last line of the file was.

#!/usr/bin/perl -w
use strict;
while(<>){}
print "Last line number was $.\n";
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If you also want to fine out how many characters there were, you'd add something to count the length of each line:

#!/usr/bin/perl -w
use strict;
my $totalLength = 0;
while(<>){$totalLength += length($_);}
print "Last line number was $.\n";
print "Total length was $totalLength\n";
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I haven't tested this code; don't know if it works or not. I'll leave that up to you. Play around. See what works. Read that Perl book. Try stuff, and come ask questions when you get stuck, and not before.

#!/bin/perl 
use strict;
use warnings;

my $chars = 0;
my $lines = 0; 
while (<>) {
  $chars += length;
  $lines ++;
}

print "$chars $lines\n";
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If you want to open the files within the Perl script instead use the open() function.

$ wc -l existing_file > another_file
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#!/usr/bin/perl -w

my $file = shift;
my @cmd = ( "wc",  "-l",  $file );
system( @cmd );
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use strict;
my $txt = do{ local $/;<>}; # slurp file from the cmd line
my $lines = split /\n/,$txt; # use split in scalar context
my $chars = length($txt); # find length of whole text
print "Chars = $chars Lines = $lines\n";
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