Question

In perl, I’m only familiar with using the usual

chomp(my $ip = <>);

If this $ip is “words separated by space”, I’d have to use split to get “words”, “separated”, “by” and “space”.

Is there a way to read word by word in the first place?

Answer 1

Setting the input record separator $/ to space will read “word by word”. You may find the results counter-intuitive, so be careful what you wish for.

Try for example:

perl -nwe 'BEGIN { $/ = " ";} print "Line: $_"'

It will read from stdin, and print it back to you, but one word at the time. However, as you shall notice, newline (pressing ENTER) is still quite an integral part of the process.

$/ cannot be smart, however. It’s just the character(s) we use to tell input records apart, and it does affect a good many other things besides STDIN, so using it will most likely confuse you. Unless, of course, you use it locally, and only exactly where you want it.

{  # make this part lexically scoped
    local $/ = " ";  # use local version of $/
    while (<>) {
        chomp(my $ip = $_);  # note that chomp removes space instead
    }
}  # End of scope, $/ is back to normal