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Re^3: A refactoring trap

by redlemon (Hermit)
on Aug 17, 2005 at 08:14 UTC ( #484338=note: print w/replies, xml ) Need Help??

in reply to Re^2: A refactoring trap
in thread A refactoring trap

Hmmm, you're right. It doesn't break.

The reason is that blank lines are not truely blank, of course. You're saved by the fact that a blank line still contains the "\n".


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Re^4: A refactoring trap
by lidden (Curate) on Aug 17, 2005 at 09:53 UTC
    No it still works with chomp:
    while(chomp (my $line = <DATA>)){
    At least with newer perl versions. Tried with perl5.8.6.
      No it still works with chomp

      To understand why this works, take a look at the return value for chomp. Hint: it's not the string with newlines missing.

      The problem with while (my $line = <DATA>) {} is real, it's just obscure. As hinted, it only happens when you get a line with a false value and no newline. Sometimes this happens at the end of a file. Sometimes it happens for other reasons. It usually doesn't cause any actual problems, but certainly is something to look out for.

        The problem with while (my $line = <DATA>) {} is real, it's just obscure

        ARRRRGH! :-)

        As has already been pointed out this hasn't been a problem for some time. Perl automatically adds the defined for you, as you can easily see by running:

        a% perl -MO=Deparse -e 'while (my $line = <DATA>) {}' while (defined(my $line = <DATA>)) { (); } __DATA__ -e syntax OK

        This hasn't been a problem for Perl for quite some time, and I wish people wouldn't keep saying it is ;-)

      With this method you'll never be able to loop through the last line.

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[LanX]: should this be considered? Re: Parsing .txt into arrays
[LanX]: and this Re^4: Hash user input
[pryrt]: LanX, I would vote "keep" if it were considered: it's not helpful, but it could be taken multiple ways, not all of which are offenseive...
[pryrt]: 1nickt: if you are checking for valid user IDs, then I wouldn't care about the difference between 1.0 and 1: I would take either as a valid representation of the integer user ID#1
[LanX]: and this Re^2: extract column data
[Lady_Aleena]: I have two sub recurse { my ($directory, $other_var) = @_; my @files = file_list($directo ry); for my $file (@files) { if (-f $file) { do "stuff"; } if (-d $file) { recurse(" $directory/$file" , $other_var); } } } This was when I hated File::Find.
[tobyink]: 1nickt: your code?
[LanX]: pryrt: yeah, that's why I didn't consider, but the last >10 anonymous posts are from the same troll-person
[jdporter]: is there a module for expanding tabs in text?
[jdporter]: A: yes.

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