Why does this code not work? (split, array slice)
What to do when you try to split a string and get several fields at once but it does not work?
I've received the following two examples in a short intervallum asking Why does this code not work?.
In order to answer the questions I actually need to know what is the expected result, something the person asking this question missed to provide, but luckily in these examples it seemed to be obvious.
I got two snippets and ran both of them:
my $str = "root:*:0:0:System Administrator:/var/root:/bin/sh"; my $indexes="0,4"; ######## HERE#### my ($username, $real_name) = (split /:/, $str)[$indexes]; ##and HERE## print "$username\n"; print "$real_name\n";
(The HERE marks were in the code when I got it.)
$ perl split_on_the_fly.pl root
In this case the author wanted to split the $str string and copy the fields 0 and 4. Effectively doing what I called split on the fly.
my $str = "root:*:0:0:System Administrator:/var/root:/bin/sh"; my @fields = split /:/, $str; $num="0,4"; my ($username, $real_name) = @fields[$num]; print "$username\n"; print "$real_name\n";
$ perl array_slice_not_working.pl root
In the second example, apparently in an attempt to simplify the code and find the problem that way, the author has first created an array from the list returned by the split and then tried to use array slicing.
The solution is in another article.
Published on 2018-02-20