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Re: Problems with Subroutines

by Juerd (Abbot)
on Sep 01, 2011 at 00:12 UTC ( #923551=note: print w/replies, xml ) Need Help??

in reply to Problems with Subroutines

Beginning Perl has a chapter on subroutines; it's chapter 8 and it answers all your questions.

The error you're getting is caused by trying to read from a filehandle that was opened for output only. You can't do that. Although it's possible to open a filehandle that you can both write to and read from, that's an advanced topic and not suited for beginners.

Also, don't write to the file that you're still reading. Strange things will happen. Instead, write to a new file and rename that when you're done and sure that the old file may be removed. This also avoids some race conditions, and incomplete files if the program should crash before it's done writing.

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[james28909]: ok maybe i need to ask this question in sopw and not CB but here goes
[james28909]: i am manually parsing html, and am trying to wrap my head around keeping up with tag counts
[james28909]: i can extract a certain tree manually by regexing the html file for a starting anchor, then i send the position of the match to a sub and then seek to that position in the file and keep up with div tags (for now)
[james28909]: how can i manage multiple tags? other than div?
[james28909]: i count the div and /div and when count == 0 it means i have got that nested tree

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