Re: How smart is 'seek $fh, $pos, 0'?

Doing this from memory - sorry, cannot find a source reference (which would be the ideal authority for your question). Given some of the grey hair now showing on my head, I have to ask - what device do you have open and are calling a seek() against? If it were an old tape drive (perhaps even new ones?) or other sequential access medium, you would need to seek to the beginning of file then to the position. Given a random access medium, you can "simply" (with a bit of additional housekeeping around buffers and such) reset the current file pointer on the handle. So, "It Depends™". [update] Additionally, some devices do not allow seeking backwards and will throw an error if attempted.

--MidLifeXis

Comment on Re: How smart is 'seek $fh, $pos, 0'?

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Re^2: How smart is 'seek $fh, $pos, 0'? by Monk::Thomas (Friar) on May 27, 2015 at 13:18 UTC
This question is not backup-related so thankfully I don't have to concern myself with tape drives. The code is expected to handle a specific file format (Bethesda .esm and .esp files) and therefor the filehandle is expected to point to a file on a random access media (disk drive). The most common case would be sequentially processing the records, but I'd like to also be able to process the records out of order (e.g. skip uninteresting ones).	[reply]

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Re^2: How smart is 'seek $fh, $pos, 0'?
by Monk::Thomas (Friar) on May 27, 2015 at 13:18 UTC

This question is not backup-related so thankfully I don't have to concern myself with tape drives. The code is expected to handle a specific file format (Bethesda .esm and .esp files) and therefor the filehandle is expected to point to a file on a random access media (disk drive).

The most common case would be sequentially processing the records, but I'd like to also be able to process the records out of order (e.g. skip uninteresting ones).

[reply]