Date: Sun, 11 Apr 1999 16:33:35 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: John Milford <jwm@CSUA.Berkeley.EDU> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: read() and pread() syscalls Message-ID: <199904112333.QAA08352@apollo.backplane.com> References: <199904112116.OAA22352@soda.CSUA.Berkeley.EDU>
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: Should read() be turned into a library function now that we
:have pread(), and read() is a proper subset of pread()? I am not sure
:if this is a POSIX compliance issue, but I've been digging around in
:this code recently, and it seems that there is a lot of overlap in the
:read system calls, and we might want to consider doing something
:similar to the approach taken with wait(). I could understand that
:this case is different so we may not want to be doing conversion of
:read() or readv() into a hypothetical preadv(), but I can see no issue
:with converting read()'s into pread()'s.
:
: I am willing to make this change and submit diffs, if it is
:something that makes sense to folks on the list.
:
:
: --John
No. This would screw up backwards compatibility and, besides,
read()'s semantics cannot be simulated with pread() because
read() updates the offset stored in the file descriptor and
pread() does not.
-Matt
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