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up vote 0 down vote favorite

I have a question about Perl more out of curiosity than necessity. I have seen there are many ways to do a lot of things in Perl, a lot of the time the syntax seems unintuitive to me (I've seen a few one liners doing som impressive stuff).

So.. I know the function split returns an array. My question is, how do I go about printing the first element of this array without saving it into a special variable? Something like $(split(" ",$_))[0] ... but one that works.

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2  
substr() doesn't return an array, it returns a string. –  Barmar May 23 '13 at 23:44
1  
Perhaps you meant to say that split returns an array? –  Lorkenpeist May 23 '13 at 23:46
    
Yes I meant split, my bad –  Karlo May 23 '13 at 23:54

3 Answers 3

up vote 2 down vote accepted

This should do it:

print ((split(" ", $_))[0]);

You need one set of parentheses to allow you to apply array indexing to the result of a function. The outer parentheses are needed to get around special parsing of print arguments.

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up vote 4 down vote

You're 99% there

$ perl -de0

Loading DB routines from perl5db.pl version 1.33
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

main::(-e:1):   0
  DB<1> $a = "This is a test"

  DB<2> $b = (split(" ",$a))[0]

  DB<3> p $b
This
  DB<4> p "'$b'"
'This'
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He said he wanted to print it without assigning to a variable. –  Barmar May 24 '13 at 0:01
up vote 0 down vote

Try this out to print the first element of a whitespace separated list. The \s+ regex matches one or more whitespace characters to split on.

 echo "1 2 3 4" | perl -pe 'print +(split(/\s+/, $_))[0]'

Also, see this related post.

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