On Wed, 2010-06-30, Carl Banks wrote:
On Jun 28, 2:44 am, Gregory Ewing greg.ew...@canterbury.ac.nz wrote:
Carl Banks wrote:
Indeed, strncpy does not copy that final NUL if it's at or beyond the
nth element. Probably the most mind-bogglingly stupid thing about the
standard C library, which has lots of mind-boggling stupidity.
I don't think it was as stupid as that back when C was
designed. Every byte of memory was precious in those days,
and if you had, say, 10 bytes allocated for a string, you
wanted to be able to use all 10 of them for useful data.
So the convention was that a NUL byte was used to mark
the end of the string *if it didn't fill all the available
space*.
I can't think of any function in the standard library that observes
that convention,
Me neither, except strncpy(), according to above.
which inclines me to disbelieve this convention ever
really existed. If it did, there would be functions to support it.
Maybe others existed, but got killed off early. That would make
strncpy() a living fossil, like the Coelacanth ...
For that matter, I'm not really inclined to believe bytes were *that*
precious in those days.
It's somewhat believable. If I handled thousands of student names in a
big C array char[30][], I would resent the fact that 1/30 of the
memory was wasted on NUL bytes. I'm sure plenty of people have done what
Gregory suggests ... but it's not clear that strncpy() was designed to
support those people.
I suppose it's all lost in history.
/Jorgen
--
// Jorgen Grahn grahn@ Oo o. . .
\X/ snipabacken.se O o .
--
http://mail.python.org/mailman/listinfo/python-list
