$str = "Ipod batteries for Apple Ipod PDAs. Replacement batteries from
+ Laptops for Less.com.url";
$short = substr($str, 0, 20);
[download]

What if i want to do it with regexp, is there a way to do it like that?

Your posted code will work if you remove the space after the comma in your regex.

/^(.{1, 20}).*/; # doesn't work
/^(.{1,20}).*/;  # does work
/^(.{1,20})/;    # even easier
[download]

May the Force be with you

Yes, but why? It works fine, but substr is quicker and easier to understand.

my $short = ( m/^(.{1,20})/ ) ? $1 : '';
[download]

...or...

my( $short ) = m/^(.{0,20})/;
[download]




Dave

What if i want to do it with regexp, is there a way to do it like that?

What if I was given a perfectly good working solution, and then I said "No, I want to do it some other way"? Would people think I was asking a homework question? Maybe. Maybe not.

In any event, if this wasn't a homework question, you should have given more background about why substr didn't suffice, so that we know why you rejected that solution.

And it looks like I'm not the only one who wonders this.

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

Others here are better (and faster) with regexps than I. They have provided answers below. My question to you would be:
What is the reason for wanting to use a regex to perform a substr on a string when there's a substr function already?

-Yendor

IWeThey
HOPE Ride

The answer to that question depends entirely on what you consider to be the significant portion of the original string; the portion that you can't afford to lose.

Your example script attempts to just truncate the source string at 20 characters. You can do that quickly like this:

my $short_string = substr $_, 0, 20;
[download]

But that truncates your string to become: "Ipod batteries for A". Are you ok with that? Or do you need to define a more complex set of rules as to how the original string should be shortened?

By the way, there is a package that does this:

use String::Escape;

print String::Escape::elide( "Ipod batteries for Apple Ipod PDAs. Repl
+acement batteries from Laptops for Less.com.url", 20 );

# Ipod batteries...
[download]

$_ = "Ipod batteries for Apple Ipod PDAs. Replacement batteries from L
+aptops for Less.com.url";
print substr ($_, 0, 20);

/^(.{0,20})/;
print $1;
[download]

/^(.{1, 20}).*/;
$shortened_string = $1;
[download]

but that doesn't work?

my $str = '1234 6789 1234 6789 1234 6789 ';
my $printstr = substr($str, 0, 20+1);
$printstr =~ s/\W+\w*$//;
print $printstr;
[download]

EDIT: You may have to change the regex if words can include characters other than \w, such as .