1 =============
2 uinput module
3 =============
4
5 Introduction
6 ============
7
8 uinput is a kernel module that makes it possib
9 from userspace. By writing to /dev/uinput (or
10 process can create a virtual input device with
11 this virtual device is created, the process ca
12 that will be delivered to userspace and in-ker
13
14 Interface
15 =========
16
17 ::
18
19 linux/uinput.h
20
21 The uinput header defines ioctls to create, se
22 devices.
23
24 libevdev
25 ========
26
27 libevdev is a wrapper library for evdev device
28 create uinput devices and send events. libevde
29 accessing uinput directly, and should be consi
30
31 For examples and more information about libevd
32 https://www.freedesktop.org/software/libevdev/
33
34 Examples
35 ========
36
37 Keyboard events
38 ---------------
39
40 This first example shows how to create a new v
41 send a key event. All default imports and erro
42 the sake of simplicity.
43
44 .. code-block:: c
45
46 #include <linux/uinput.h>
47
48 void emit(int fd, int type, int code, int v
49 {
50 struct input_event ie;
51
52 ie.type = type;
53 ie.code = code;
54 ie.value = val;
55 /* timestamp values below are ignored */
56 ie.time.tv_sec = 0;
57 ie.time.tv_usec = 0;
58
59 write(fd, &ie, sizeof(ie));
60 }
61
62 int main(void)
63 {
64 struct uinput_setup usetup;
65
66 int fd = open("/dev/uinput", O_WRONLY |
67
68
69 /*
70 * The ioctls below will enable the devi
71 * created, to pass key events, in this
72 */
73 ioctl(fd, UI_SET_EVBIT, EV_KEY);
74 ioctl(fd, UI_SET_KEYBIT, KEY_SPACE);
75
76 memset(&usetup, 0, sizeof(usetup));
77 usetup.id.bustype = BUS_USB;
78 usetup.id.vendor = 0x1234; /* sample ven
79 usetup.id.product = 0x5678; /* sample pr
80 strcpy(usetup.name, "Example device");
81
82 ioctl(fd, UI_DEV_SETUP, &usetup);
83 ioctl(fd, UI_DEV_CREATE);
84
85 /*
86 * On UI_DEV_CREATE the kernel will crea
87 * device. We are inserting a pause here
88 * to detect, initialize the new device,
89 * the event, otherwise it will not noti
90 * to send. This pause is only needed in
91 */
92 sleep(1);
93
94 /* Key press, report the event, send key
95 emit(fd, EV_KEY, KEY_SPACE, 1);
96 emit(fd, EV_SYN, SYN_REPORT, 0);
97 emit(fd, EV_KEY, KEY_SPACE, 0);
98 emit(fd, EV_SYN, SYN_REPORT, 0);
99
100 /*
101 * Give userspace some time to read the
102 * device with UI_DEV_DESTROY.
103 */
104 sleep(1);
105
106 ioctl(fd, UI_DEV_DESTROY);
107 close(fd);
108
109 return 0;
110 }
111
112 Mouse movements
113 ---------------
114
115 This example shows how to create a virtual dev
116 mouse.
117
118 .. code-block:: c
119
120 #include <linux/uinput.h>
121
122 /* emit function is identical to of the fir
123
124 int main(void)
125 {
126 struct uinput_setup usetup;
127 int i = 50;
128
129 int fd = open("/dev/uinput", O_WRONLY |
130
131 /* enable mouse button left and relative
132 ioctl(fd, UI_SET_EVBIT, EV_KEY);
133 ioctl(fd, UI_SET_KEYBIT, BTN_LEFT);
134
135 ioctl(fd, UI_SET_EVBIT, EV_REL);
136 ioctl(fd, UI_SET_RELBIT, REL_X);
137 ioctl(fd, UI_SET_RELBIT, REL_Y);
138
139 memset(&usetup, 0, sizeof(usetup));
140 usetup.id.bustype = BUS_USB;
141 usetup.id.vendor = 0x1234; /* sample ven
142 usetup.id.product = 0x5678; /* sample pr
143 strcpy(usetup.name, "Example device");
144
145 ioctl(fd, UI_DEV_SETUP, &usetup);
146 ioctl(fd, UI_DEV_CREATE);
147
148 /*
149 * On UI_DEV_CREATE the kernel will crea
150 * device. We are inserting a pause here
151 * to detect, initialize the new device,
152 * the event, otherwise it will not noti
153 * to send. This pause is only needed in
154 */
155 sleep(1);
156
157 /* Move the mouse diagonally, 5 units pe
158 while (i--) {
159 emit(fd, EV_REL, REL_X, 5);
160 emit(fd, EV_REL, REL_Y, 5);
161 emit(fd, EV_SYN, SYN_REPORT, 0);
162 usleep(15000);
163 }
164
165 /*
166 * Give userspace some time to read the
167 * device with UI_DEV_DESTROY.
168 */
169 sleep(1);
170
171 ioctl(fd, UI_DEV_DESTROY);
172 close(fd);
173
174 return 0;
175 }
176
177
178 uinput old interface
179 --------------------
180
181 Before uinput version 5, there wasn't a dedica
182 device. Programs supporting older versions of
183 a uinput_user_dev structure and write it to th
184 configure the new uinput device. New code shou
185 but interact with uinput via ioctl calls, or u
186
187 .. code-block:: c
188
189 #include <linux/uinput.h>
190
191 /* emit function is identical to of the fir
192
193 int main(void)
194 {
195 struct uinput_user_dev uud;
196 int version, rc, fd;
197
198 fd = open("/dev/uinput", O_WRONLY | O_NO
199 rc = ioctl(fd, UI_GET_VERSION, &version)
200
201 if (rc == 0 && version >= 5) {
202 /* use UI_DEV_SETUP */
203 return 0;
204 }
205
206 /*
207 * The ioctls below will enable the devi
208 * created, to pass key events, in this
209 */
210 ioctl(fd, UI_SET_EVBIT, EV_KEY);
211 ioctl(fd, UI_SET_KEYBIT, KEY_SPACE);
212
213 memset(&uud, 0, sizeof(uud));
214 snprintf(uud.name, UINPUT_MAX_NAME_SIZE,
215 write(fd, &uud, sizeof(uud));
216
217 ioctl(fd, UI_DEV_CREATE);
218
219 /*
220 * On UI_DEV_CREATE the kernel will crea
221 * device. We are inserting a pause here
222 * to detect, initialize the new device,
223 * the event, otherwise it will not noti
224 * to send. This pause is only needed in
225 */
226 sleep(1);
227
228 /* Key press, report the event, send key
229 emit(fd, EV_KEY, KEY_SPACE, 1);
230 emit(fd, EV_SYN, SYN_REPORT, 0);
231 emit(fd, EV_KEY, KEY_SPACE, 0);
232 emit(fd, EV_SYN, SYN_REPORT, 0);
233
234 /*
235 * Give userspace some time to read the
236 * device with UI_DEV_DESTROY.
237 */
238 sleep(1);
239
240 ioctl(fd, UI_DEV_DESTROY);
241
242 close(fd);
243 return 0;
244 }
245
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