'\" t
.TH "BUXTON_GET_VALUE" "3" "buxton 1" "buxton_get_value"
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.SH "NAME"
buxton_get_value \- Get the value of a key\-name

.SH "SYNOPSIS"
.nf
\fB
#include <buxton.h>
\fR
.sp
\fB
int buxton_get_value(BuxtonClient \fIclient\fB,
.br
                     BuxtonKey \fIkey\fB,
.br
                     BuxtonCallback \fIcallback\fB,
.br
                     void *\fIdata\fB,
.br
                     bool \fIsync\fB)
\fR
.fi

.SH "DESCRIPTION"
.PP
This function is used to get the value of a key\-name for
\fIclient\fR. The key\-name is referenced by \fIkey\fR. If the layer
for \fIkey\fR is NULL, buxton will traverse layers in priority order
searching for the key-name value, selecting the value for the first
key\-name found\&. If the argument is non-NULL, the operation will
target only that layer\&. For more information on creating a
BuxtonKey to pass for \fIkey\fR, see \fBbuxton_key_create\fR(3)\&.

To retrieve the result of the operation, clients should define a
callback function, referenced by the \fIcallback\fR argument; the
callback function is called upon completion of the operation\&. The
\fIdata\fR argument is a pointer to arbitrary userdata that is passed
along to the callback function\&. Additonally, the \fIsync\fR
argument controls whether the operation should be synchronous or not;
if \fIsync\fR is false, the operation is asynchronous\&.

.SH "CODE EXAMPLE"
.nf
.sp
#define _GNU_SOURCE
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "buxton.h"

void get_cb(BuxtonResponse response, void *data)
{
	int32_t* ret = (int32_t*)data;

	if (buxton_response_status(response) != 0) {
		printf("Failed to get value\\n");
		return;
	}

	*ret = *(int32_t*)buxton_response_value(response);
}

int main(void)
{
	BuxtonClient client;
	BuxtonKey key;
	struct pollfd pfd[1];
	int r;
	int32_t gvalue = -1;
	int fd;

	if ((fd = buxton_open(&client)) < 0) {
		printf("couldn't connect\\n");
		return -1;
	}

	key = buxton_key_create("hello", "test", "user", INT32);
	if (!key) {
		return -1;
	}

	if (buxton_get_value(client, key, get_cb,
			     &gvalue, false)) {
		printf("get call failed to run\\n");
		return -1;
	}

	pfd[0].fd = fd;
	pfd[0].events = POLLIN;
	pfd[0].revents = 0;
	r = poll(pfd, 1, 5000);

	if (r <= 0) {
		printf("poll error\\n");
		return -1;
	}

	if (!buxton_client_handle_response(client)) {
		printf("bad response from daemon\\n");
		return -1;
	}

	if (gvalue >= 0) {
		printf("got value: %d\\n", gvalue);
	}

	buxton_key_free(key);
	buxton_close(client);
	return 0;
}
.fi

.SH "RETURN VALUE"
.PP
Returns 0 on success, and a non\-zero value on failure\&.

.SH "COPYRIGHT"
.PP
Copyright 2014 Intel Corporation\&. License: Creative Commons
Attribution\-ShareAlike 3.0 Unported\s-2\u[1]\d\s+2, with exception
for code examples found in the \fBCODE EXAMPLE\fR section, which are
licensed under the MIT license provided in the \fIdocs/LICENSE.MIT\fR
file from this buxton distribution\&.

.SH "SEE ALSO"
.PP
\fBbuxton\fR(7),
\fBbuxtond\fR(8),
\fBbuxton\-api\fR(7)

.SH "NOTES"
.IP " 1." 4
Creative Commons Attribution\-ShareAlike 3.0 Unported
.RS 4
\%http://creativecommons.org/licenses/by-sa/3.0/
.RE