.\" $OpenBSD: pread.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 PREAD 3
.Os
.Sh NAME
.Nm pread
.Nd atomic seek and read
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft ssize_t
.Fn pread "int filedes" "void *buf" "size_t nbytes" "off_t offset"
.Sh DESCRIPTION
The
.Fn pread
function reads
.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 reading from the same file descriptor.
.Sh RETURN VALUES
The
.Fn pread
function returns values identical to
.Xr read 2 .
.Sh SEE ALSO
.Xr read 2 ,
.Xr pthreads 3 ,
.Xr pwrite 3
.Sh STANDARDS
.Fn pread
conforms to
.St -susv2 .