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Re: inplace file editing

by ZZamboni (Curate)
on Jun 11, 2001 at 05:38 UTC ( #87385=note: print w/replies, xml ) Need Help??

in reply to inplace file editing

I think the difference does not have to do with the use of $^I, but with how $/=undef behaves when reading from the magic <> file handle. The following program:
$^I=""; undef $/; while(<>) { print "hello:\n" }
Behaves the same if I comment out the $^I line: it prints "hello" twice, except that when $^I="" it is printed to the file I give as argument, obliterating it. Printing $_ on each iteration shows that $_ contains '' (empty string) on the second iteration, so my guess is that setting $/ to undef somehow changes the way in which perl reads from <>, but I don't really have an answer...


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Re: Re: inplace file editing
by Anonymous Monk on Jun 11, 2001 at 11:40 UTC
    sorry, what i meant to say was
    $ARGV[0]="test"; $^I=""; undef $/; while(<>) { print STDOUT "hello\n" }
    (which stops hello getting printed to the file)...but it still prints twice. can ANYONE help?

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