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.TH "SYSFS_WRITE_FILE" "" "06 October 2005" "" ""

.SH NAME
sysfs_write_file \- write an attribute.
.SH SYNOPSIS
"SYNOPSIS"
.sp
\fB
.sp
ssize_t sysfs_write_file  (struct file * \fIfile\fB, const char __user * \fIbuf\fB, size_t \fIcount\fB, loff_t * \fIppos\fB);
\fR
.SH "ARGUMENTS"
.TP
\fB\fIfile\fB\fR
file pointer
.TP
\fB\fIbuf\fB\fR
data to write
.TP
\fB\fIcount\fB\fR
number of bytes
.TP
\fB\fIppos\fB\fR
starting offset
.SH "DESCRIPTION"
.PP
Similar to \fBsysfs_read_file\fR, though working in the opposite direction.
We allocate and fill the data from the user in \fBfill_write_buffer\fR,
then push it to the kobject in \fBflush_write_buffer\fR\&.
There is no easy way for us to know if userspace is only doing a partial
write, so we don't support them. We expect the entire buffer to come
on the first write. 
.SH "HINT"
.PP
if you're writing a value, first read the file, modify only the
the value you're changing, then write entire buffer back.