On FreeBSD, this is the default behaviour. According to the spec, we may
give this flag a value of zero, but I'd rather not do this. If we define
it to a non-zero value, we can always change default behaviour without
changing the ABI. This is very unlikely to happen, though.
- O_NONBLOCK flag has to be set, if it is not set, open(2) will wait for
another process opening the fifo for reading,
- Use O_WRONLY which implies that the file has to be opened _only_ for write.
This is quite tricky situation, because we allow to open a file with
O_RDONLY|O_TRUNC. O_TRUNC modifies a file, but we actually don't open
it for writing. EISDIR is also returned when we try to open a directory
O_RDONLY|O_TRUNC, which is correct.
POSIX says that "The result of using O_TRUNC with O_RDONLY is undefined.",
we choose to accept it (Solaris did the same), that's why "to be modified"
seems more accurate to me.
other systems it prevents a tty from becoming a controlling tty on the
open. O_SYNC is the POSIX name for O_FSYNC.
The Markup Police may need to tweak my references to standards.
Stop calling system calls "function calls".
Use "The .Fn system call" a-la "The .Nm utility".
When referring to a non-BSD implementation in
the HISTORY section, call syscall a function,
to be safe.
Tor created a while ago, removes the raw I/O piece (that has cache coherency
problems), and adds a buffer cache / VM freeing piece.
Essentially this patch causes O_DIRECT I/O to not be left in the cache, but
does not prevent it from going through the cache, hence the 80%. For
the last 20% we need a method by which the I/O can be issued directly to
buffer supplied by the user process and bypass the buffer cache entirely,
but still maintain cache coherency.
I also have the code working under -stable but the changes made to sys/file.h
may not be MFCable, so an MFC is not on the table yet.
Submitted by: tegge, dillon
track.
The $Id$ line is normally at the bottom of the main comment block in the
man page, separated from the rest of the manpage by an empty comment,
like so;
.\" $Id$
.\"
If the immediately preceding comment is a @(#) format ID marker than the
the $Id$ will line up underneath it with no intervening blank lines.
Otherwise, an additional blank line is inserted.
Approved by: bde
in a bunch of man pages.
Use the correct .Bx (BSD UNIX) or .At (AT&T UNIX) macros
instead of explicitly specifying the version in the text
in a bunch of man pages.
