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author | dt <dt@FreeBSD.org> | 1999-04-11 21:14:40 +0000 |
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committer | dt <dt@FreeBSD.org> | 1999-04-11 21:14:40 +0000 |
commit | aa2a8a165f46ceee1384f0dcb21173a1aba008ea (patch) | |
tree | 1d55f0b77dd575ad46d66665a4eed3b8a3de038f /lib/libc/sys/write.2 | |
parent | cb5131e1df64c490ed29cd4246bffd8700ce4821 (diff) | |
download | FreeBSD-src-aa2a8a165f46ceee1384f0dcb21173a1aba008ea.zip FreeBSD-src-aa2a8a165f46ceee1384f0dcb21173a1aba008ea.tar.gz |
Document pread() and pwrite().
Obtained from: NetBSD (mostly)
Diffstat (limited to 'lib/libc/sys/write.2')
-rw-r--r-- | lib/libc/sys/write.2 | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/lib/libc/sys/write.2 b/lib/libc/sys/write.2 index f8d8063..240f970 100644 --- a/lib/libc/sys/write.2 +++ b/lib/libc/sys/write.2 @@ -36,7 +36,8 @@ .Os BSD 4 .Sh NAME .Nm write , -.Nm writev +.Nm writev , +.Nm pwrite .Nd write output .Sh SYNOPSIS .Fd #include <sys/types.h> @@ -46,6 +47,8 @@ .Fn write "int d" "const void *buf" "size_t nbytes" .Ft ssize_t .Fn writev "int d" "const struct iovec *iov" "int iovcnt" +.Ft ssize_t +.Fn pwrite "int d" "const void *buf" "size_t nbytes" "off_t offset" .Sh DESCRIPTION .Fn Write attempts to write @@ -61,6 +64,9 @@ from the buffers specified by the members of the .Fa iov array: iov[0], iov[1], ..., iov[iovcnt\|-\|1]. +.Fn Pwrite +performs the same function, but writes to the specified position in +the file without modifying the file pointer. .Pp For .Fn writev , @@ -168,9 +174,10 @@ is returned. Otherwise a -1 is returned and the global variable .Va errno is set to indicate the error. .Sh ERRORS -.Fn Write +.Fn Write , +.Fn writev , and -.Fn writev +.Fn pwrite will fail and the file pointer will remain unchanged if: .Bl -tag -width Er .It Bq Er EBADF @@ -229,6 +236,16 @@ values in the .Fa iov array overflowed a 32-bit integer. .El +.Pp +The +.Fn pwrite +call may also return the following errors: +.Bl -tag -width Er +.It Bq Er EINVAL +The specified file offset is invalid. +.It Bq Er ESPIPE +The file descriptor is associated with a pipe, socket, or FIFO. +.El .Sh SEE ALSO .Xr fcntl 2 , .Xr lseek 2 , @@ -240,8 +257,19 @@ The .Fn write function call is expected to conform to .St -p1003.1-90 . +The +.Fn writev +and +.Fn pwrite +functions are expected to conform to +.St -xpg4.2 . .Sh HISTORY The +.Fn pwrite +function call +appeared in +.At V.4 . +The .Fn writev function call appeared in |