.TH WRITE 2
.CT 2 file_io comm_proc
.SH NAME
write \(mi write on a file
.SH SYNOPSIS
.nf
.B int write(fildes, buffer, nbytes)
.B char *buffer;
.fi
.SH DESCRIPTION
.I Write
writes
.I nbytes
bytes of data starting at
.I buffer
to the file associated with
.I fildes
at the file pointer location.
The file pointer is advanced by the number of bytes written.
.PP
The number of characters actually written is returned.
It should be regarded as an error
if this is not the same as requested.
.PP
If 
.IR fildes
refers to an append-only file (see
.IR stat (2)),
the file pointer is set to the end of the
file before writing.
.PP
Writes which are aligned with file system blocks
are more efficient than others; see
.IR filsys (5).
.SH "SEE ALSO"
.IR creat (2),
.IR open (2), 
.IR pipe (2), 
.IR select (2)
.SH DIAGNOSTICS
.BR EBADF ,
.BR EFAULT ,
.BR EINTR ,
.BR EINVAL ,
.BR EIO ,
.BR ELAB ,
.BR ENXIO ,
.BR EPIPE ,
.BR EROFS
.SH BUGS
A
.I write
call may fail because of a prior call to
.IR lseek .