如何读取Linux键值,输入子系统,key,dev/input/event,dev/event,C语言键盘?
这里先上一段代码,自己拿到linux系统运行就可以,注意代码中keys_fd = open("/dev/input/event2", O_RDONLY); 这里去你的/dev/input/event2的event事件,去查看你的键盘事件是那一个,如果是event3那么你改成event3好了。这里给一个命令你去查看 cat /proc/bus/usb/devices
http://www.jb51.net/LINUXjishu/30628.html如果还是查找不到请看这个链接。 在一个终端中运行下面的代码,再打开另开一个中按下按键,然后查看第一个终端中输出的信息你就知道是怎么回事了,哈哈,是不是获取你按下键盘的键值了??? oh yeah! 建议再去查看一下linux下input 子系统的介绍和查看一下input.h文件,网上一大堆,你一查你就知道了是怎么回事了。
#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <sys/types.h> #include <fcntl.h> #include <errno.h> #include <time.h> #include <linux/input.h> int main() { int keys_fd; char ret[2]; struct input_event t; keys_fd = open("/dev/input/event2", O_RDONLY); if (keys_fd <= 0) { printf("open /dev/input/event2 device error!\n"); return 0; } while (1) { if (read(keys_fd, &t, sizeof (t)) == sizeof (t)) { if (t.type == EV_KEY) if (t.value == 0 || t.value == 1) { printf("key %d %s\n", t.code, (t.value) ? "Pressed" : "Released"); if (t.code == KEY_ESC) break; } } } close(keys_fd); return 0; }好了,这里给出一个重量级的代码,比上面的更完整.,自己拿去运行好好分析一下就知道怎么回事了....
/* * Copyright 2002 Red Hat Inc., Durham, North Carolina. * * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation on the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial * portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NON-INFRINGEMENT. IN NO EVENT SHALL RED HAT AND/OR THEIR SUPPLIERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * * This is a simple test program that reads from /dev/input/event*, * decoding events into a human readable form. */ /* * Authors: * Rickard E. (Rik) Faith <faith@redhat.com> * */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <sys/types.h> #include <fcntl.h> #include <errno.h> #include <time.h> #include <linux/input.h> struct input_event event; int main(int argc, char **argv) { char name[64]; /* RATS: Use ok, but could be better */ char buf[256] = { 0, }; /* RATS: Use ok */ unsigned char mask[EV_MAX / 8 + 1]; /* RATS: Use ok */ int version; int fd = 0; int rc; int i, j; char *tmp; #define test_bit(bit) (mask[(bit)/8] & (1 << ((bit)%8))) for (i = 0; i < 32; i++) { sprintf(name, "/dev/input/event%d", i); if ((fd = open(name, O_RDONLY, 0)) >= 0) { ioctl(fd, EVIOCGVERSION, &version); ioctl(fd, EVIOCGNAME(sizeof(buf)), buf); ioctl(fd, EVIOCGBIT(0, sizeof(mask)), mask); printf("%s\n", name); printf(" evdev version: %d.%d.%d\n", version >> 16, (version >> 8) & 0xff, version & 0xff); printf(" name: %s\n", buf); printf(" features:"); for (j = 0; j < EV_MAX; j++) { if (test_bit(j)) { const char *type = "unknown"; switch (j) { case EV_KEY: type = "keys/buttons"; break; case EV_REL: type = "relative"; break; case EV_ABS: type = "absolute"; break; case EV_MSC: type = "reserved"; break; case EV_LED: type = "leds"; break; case EV_SND: type = "sound"; break; case EV_REP: type = "repeat"; break; case EV_FF: type = "feedback"; break; } printf(" %s", type); } } printf("\n"); close(fd); } } if (argc > 1) { sprintf(name, "/dev/input/event%d", atoi(argv[1])); if ((fd = open(name, O_RDWR, 0)) >= 0) { printf("%s: open, fd = %d\n", name, fd); for (i = 0; i < LED_MAX; i++) { event.time.tv_sec = time(0); event.time.tv_usec = 0; event.type = EV_LED; event.code = i; event.value = 0; write(fd, &event, sizeof(event)); } while ((rc = read(fd, &event, sizeof(event))) > 0) { printf("%-24.24s.%06lu type 0x%04x; code 0x%04x;" " value 0x%08x; ", ctime(&event.time.tv_sec), event.time.tv_usec, event.type, event.code, event.value); switch (event.type) { case EV_KEY: if (event.code > BTN_MISC) { printf("Button %d %s", event.code & 0xff, event.value ? "press" : "release"); } else { printf("Key %d (0x%x) %s", event.code & 0xff, event.code & 0xff, event.value ? "press" : "release"); } break; case EV_REL: switch (event.code) { case REL_X: tmp = "X"; break; case REL_Y: tmp = "Y"; break; case REL_HWHEEL: tmp = "HWHEEL"; break; case REL_DIAL: tmp = "DIAL"; break; case REL_WHEEL: tmp = "WHEEL"; break; case REL_MISC: tmp = "MISC"; break; default: tmp = "UNKNOWN"; break; } printf("Relative %s %d", tmp, event.value); break; case EV_ABS: switch (event.code) { case ABS_X: tmp = "X"; break; case ABS_Y: tmp = "Y"; break; case ABS_Z: tmp = "Z"; break; case ABS_RX: tmp = "RX"; break; case ABS_RY: tmp = "RY"; break; case ABS_RZ: tmp = "RZ"; break; case ABS_THROTTLE: tmp = "THROTTLE"; break; case ABS_RUDDER: tmp = "RUDDER"; break; case ABS_WHEEL: tmp = "WHEEL"; break; case ABS_GAS: tmp = "GAS"; break; case ABS_BRAKE: tmp = "BRAKE"; break; case ABS_HAT0X: tmp = "HAT0X"; break; case ABS_HAT0Y: tmp = "HAT0Y"; break; case ABS_HAT1X: tmp = "HAT1X"; break; case ABS_HAT1Y: tmp = "HAT1Y"; break; case ABS_HAT2X: tmp = "HAT2X"; break; case ABS_HAT2Y: tmp = "HAT2Y"; break; case ABS_HAT3X: tmp = "HAT3X"; break; case ABS_HAT3Y: tmp = "HAT3Y"; break; case ABS_PRESSURE: tmp = "PRESSURE"; break; case ABS_DISTANCE: tmp = "DISTANCE"; break; case ABS_TILT_X: tmp = "TILT_X"; break; case ABS_TILT_Y: tmp = "TILT_Y"; break; case ABS_MISC: tmp = "MISC"; break; default: tmp = "UNKNOWN"; break; } printf("Absolute %s %d", tmp, event.value); break; case EV_MSC: printf("Misc"); break; case EV_LED: printf("Led"); break; case EV_SND: printf("Snd"); break; case EV_REP: printf("Rep"); break; case EV_FF: printf("FF"); break; break; } printf("\n"); } printf("rc = %d, (%s)\n", rc, strerror(errno)); close(fd); } } return 0; }
linux下input event事件,可以用后台截取键盘按下的键值,后台截取数据.....input.h
原文地址:http://blog.csdn.net/chenxun_2010/article/details/41722119