preview a filehandle's next character WITHOUT changing the position of the handle


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preview a filehandle's next character WITHOUT changing the position of the handle

by chengj86 (Initiate)

on Nov 09, 2011 at 20:27 UTC ( [id://937206]=perlquestion: print w/replies, xml )

Need Help??

chengj86 has asked for the wisdom of the Perl Monks concerning the following question:

Hi, What i'm trying to do here is to preview the next character in the filehandle WITHOUT changing its position (in a WHILE loop). (so no getc) I have no idea how to do this. anybody knows any tricks??? Thx A LOT! Cheng

Comment on preview a filehandle's next character WITHOUT changing the position of the handle

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Re: preview a filehandle's next character WITHOUT changing the position of the handle by ikegami (Patriarch) on Nov 09, 2011 at 20:33 UTC
To my knowledge, the system provides no such call. At best, you can "unread" what you read by seeking back, or by playing with the buffers. Update: Actually, linux provides `pread`: "Read from a file descriptor at a given offset. The file offset is not changed." I don't see any existing modules providing access to it, though. It requires a seekable handle.	[reply] [d/l]
Re^2: preview a filehandle's next character WITHOUT changing the position of the handle by BrowserUk (Patriarch) on Nov 09, 2011 at 20:48 UTC
Ignore this. PM is royally screwed up at the moment.	[reply]

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