Re: How can I read and print lines that has only one word from a file

[cjf]

So you want to open a file and print out all lines that only contain one word? If so, this should work:

open FILE, "file.txt" or die $!;

while (<FILE>) {
    chomp;
    print "$_\n" if $_ =~ /^(\w+)$/;
}

close FILE;

Let me know if you have any questions.

Update: ++'s to tadman for the improvements below.

[tadman]

Or alternatively, being a little more accomodating:

while (<>)
{
     print if (/^\s*\S+\s*$/);
}

You can call this with either one file, or as many as you like. The double-angle-brackets just read in anything from @ARGV. Further, it looks for a single group of "non-space" characters. This includes things with punctuation and such.

[Anonymous Monk]

Yes I have a question. Does /^(\w+)$/ mean that lines that start with one word or contain one word?

[tadman]

It means, literally, "start of line(^), followed by one-or-more word-characters(\w+), followed by end of line($)". This is one possible definition of "one word on line".