Re: Re: Re: How do I verify that a copied file's contents did not corrupt/modify?

Works like a charm! A few questions to help illuminate my mind, if I may.

I'm looking at the perlfunc entry for open, and I remain a little hazy regarding the subtle difference between ">" truncating and "+>" clobbering. I'm digging through the holy texts and references now, but if you care to pass more wisdom my way ...

The sysseek is a nice touch. I take it that since $outFile was not at the beginning of the file when I passed the filehandle to Digest::MD5, it somehow changed the hashing algorithm's output? Like only hashing from the current position to the end?

THX!
Dex

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Re: Re: Re: Re: How do I verify that a copied file's contents did not corrupt/modify? by jeroenes (Priest) on Mar 14, 2001 at 20:11 UTC
Dex, I actually had to look it up myself (Shhh... don't tell anybody). The + modifies the > or < redirections to 'both ways'. That means, '+>' first opens for writing, but allows reading as well. So you start with an empty file, guaranteed. '+<' the other way around. Your 2nd question: Yes. With the remark that you're already at the end, so there is very little to hash on ;-). Cheers Jeroen "We are not alone"(FZ)	[reply]

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Re: Re: Re: Re: How do I verify that a copied file's contents did not corrupt/modify?
by jeroenes (Priest) on Mar 14, 2001 at 20:11 UTC

I actually had to look it up myself (Shhh... don't tell anybody). The + modifies the > or < redirections to 'both ways'. That means, '+>' first opens for writing, but allows reading as well. So you start with an empty file, guaranteed. '+<' the other way around.

Your 2nd question: Yes. With the remark that you're already at the end, so there is very little to hash on ;-).

Cheers

Jeroen

"We are not alone"(FZ)

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