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Re^4: A refactoring trap

by lidden (Deacon)
on Aug 17, 2005 at 09:53 UTC ( #484350=note: print w/ replies, xml ) Need Help??


in reply to Re^3: A refactoring trap
in thread A refactoring trap

No it still works with chomp:

while(chomp (my $line = <DATA>)){
At least with newer perl versions. Tried with perl5.8.6.


Comment on Re^4: A refactoring trap
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Re^5: A refactoring trap
by !1 (Hermit) on Aug 17, 2005 at 18:05 UTC
    With this method you'll never be able to loop through the last line.
Re^5: A refactoring trap
by revdiablo (Prior) on Aug 17, 2005 at 20:11 UTC
    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 ;-)

        this hasn't been a problem for some time. Perl automatically adds the defined for you

        Aye, I wrongly thought this only happened in the case of while (<FH>) {}. Sorry about the confusion.

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