.\" $OpenBSD: pwrite.3,v 1.8 2000/04/15 02:15:26 aaron Exp $
.\" David Leonard <d@openbsd.org>, 1998. Public domain.
.Dd September 7, 1998
.Dt PWRITE 3
.Os
.Sh NAME
.Nm pwrite
.Nd atomic seek and write
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft ssize_t
.Fn pwrite "int filedes" "void *buf" "size_t nbytes" "off_t offset"
.Sh DESCRIPTION
The
.Fn pwrite
function writes
.Fa nbyte
bytes from offset
.Fa offset
in the file opened on file descriptor
.Fa filedes .
.Pp
This function is provided for use in a threaded, parallel I/O
environment, where race conditions may exist between two threads
non-atomically seeking and writing to the same file descriptor.
.Sh RETURN VALUES
The
.Fn pwrite
function returns values identical to
.Xr write 2 .
.Sh SEE ALSO
.Xr write 2 ,
.Xr pread 3 ,
.Xr pthreads 3
.Sh STANDARDS
.Fn pwrite
conforms to
.St -susv2 .