SPUG: NDBM questions
bjturner at mac.com
Thu Mar 14 18:19:51 CST 2002
On Thursday, March 14, 2002, at 02:47 PM, Benjamin Franks wrote:
> Ok, now for the question. I'm writing a Perl application that
> reads from
> the same database. However, if I tie a %hash to the ndbm file and then
> print out the keys and values, the values are garbled. Is there a Perl
> equivalent to the C memcpy for byte string copies?
You'll need to use perl's 'unpack' function to translate
from these C structures into something perlish. perldoc -f
unpack will give you the lowdown, though there's a lot there and
it'll probably take some fiddling. You may wish to separate the
unpack part of the problem from the ndbm stuff and focus first
on just unpacking the C structure from a flat file into perl.
> One more question. Let's say I open a handle to this database
> (or a file
> in general) in a parent and fork off children. The children
> inherit the
> open handle. Now, if the children close the handle explicitly,
> does that
> mean it closed for the parent as well? Or will the parent
> handle remain
The children have their own *copies* of the file
descriptors, and when they close their *copies*, the parents'
file descriptors are not affected. In other words, the parent's
handle will still remain open.
Benjamin John Turner | bjturner at bigfoot.com
http://www.usfca.edu/turner/ | bjturner at mac.com
"The happiest of people don't necessarily have the best of
everything; they just make the most of everything that comes
along their way."
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