'\" t
.\"     Title: usb_string
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: January 2017
.\"    Manual: USB Core APIs
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "USB_STRING" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "USB Core APIs"
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.SH "NAME"
usb_string \- returns UTF\-8 version of a string descriptor
.SH "SYNOPSIS"
.HP \w'int\ usb_string('u
.BI "int usb_string(struct\ usb_device\ *\ " "dev" ", int\ " "index" ", char\ *\ " "buf" ", size_t\ " "size" ");"
.SH "ARGUMENTS"
.PP
\fIdev\fR
.RS 4
the device whose string descriptor is being retrieved
.RE
.PP
\fIindex\fR
.RS 4
the number of the descriptor
.RE
.PP
\fIbuf\fR
.RS 4
where to put the string
.RE
.PP
\fIsize\fR
.RS 4
how big is
\(lqbuf\(rq?
.RE
.SH "CONTEXT"
.PP
!in_interrupt ()
.SH "DESCRIPTION"
.PP
This converts the UTF\-16LE encoded strings returned by devices, from
\fBusb_get_string_descriptor\fR, to null\-terminated UTF\-8 encoded ones that are more usable in most kernel contexts\&. Note that this function chooses strings in the first language supported by the device\&.
.PP
This call is synchronous, and may not be used in an interrupt context\&.
.SH "RETURN"
.PP
length of the string (>= 0) or usb_control_msg status (< 0)\&.
.SH "COPYRIGHT"
.br