Linux中c语言实现获取wifi状态

2024-02-24 18:11| 来源: 网络整理| 查看: 265

Linux中c语言实现获取wifi状态 Linux中c语言实现获取wifi状态1、c语言实现2、命令抓取方式 Linux中c语言实现获取wifi状态

获取wifi信息有两种方案，参考ifconfig程序使用c语言实现，或者使用命令抓取关键词。

1、c语言实现

废话不多说直接上代码。

#include #include #include #include #include #include #include #include #include #include #define NET_PORT 53 #define NET_IP "8.8.8.8" //谷歌DNS int main() { int sockfd; struct iwreq wreq; struct iw_statistics stats; char buffer[32]; int in_len=0; struct sockaddr_in servaddr; memset(buffer, 0, 32); memset(&stats, 0, sizeof(stats)); memset(&wreq, 0, sizeof(wreq)); strcpy(wreq.ifr_name, "wlan0"); if((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) //建立socket，用于接收来自ioctl函数的消息。由于是sock_DGRAM,所以是UDP。如果是SOCK_STREAM,则是TCP。 { perror("Could not create simple datagram socket"); exit(EXIT_FAILURE); } in_len = sizeof(struct sockaddr_in); /*设置默认服务器的信息*/ servaddr.sin_family = AF_INET; servaddr.sin_port = htons(NET_PORT); servaddr.sin_addr.s_addr = inet_addr(NET_IP); memset(servaddr.sin_zero,0,sizeof(servaddr.sin_zero)); /*connect 函数*/ if(connect(sockfd,(struct sockaddr* )&servaddr,in_len) < 0 ) { printf("not connect to internet!\n "); close(sockfd); return 0; }else{ printf(" connect ok! \n"); } //ioctl获取Signal level wreq.u.data.pointer = &stats; wreq.u.data.length = sizeof(iw_statistics); if(ioctl(sockfd, SIOCGIWSTATS, &wreq) == -1) { perror("Error performing SIOCGIWSTATS"); close(sockfd); exit(EXIT_FAILURE); }else{ // IW_QUAL_DBM表示Level + Noise are dBmm printf("Signal level%s is %d%s.\n",(stats.qual.updated & IW_QUAL_DBM ? " (in dBm)" :""),(signed char)stats.qual.level, (stats.qual.updated & IW_QUAL_LEVEL_UPDATED ? " (updated)" :"")); } //ioctl获取essid wreq.u.essid.pointer = buffer;//如果不写这行可能会错误 wreq.u.essid.length = 32; if (ioctl(sockfd,SIOCGIWESSID, &wreq) == -1) { perror("IOCTL SIOCGIWESSID Failed,error"); exit(2); }else { //printf("IOCTL SIOCGIWESSID Successfull\n"); printf("The essid is:%s\n",wreq.u.essid.pointer); //network name } close(sockfd); return 0; }

首先建立socket，函数原型即：int socket(int domain, int type, int protocol)，再建立connect连接，我是用的谷歌的DNS:8.8.8.8来测试连接外网。如果连接成功后就可获取wifi名字和强度了。接下来使用ioctl函数，ioctl是设备驱动程序中对设备的I/O通道进行管理的函数。所谓对I/O通道进行管理，就是对设备的一些特性进行控制，它的调用个数如下： int ioctl(int fd, ind cmd, …)；其中fd是用户程序打开设备时使用open函数返回的文件标示符，cmd是用户程序对设备的控制命令，至于后面的省略号，那是一些补充参数，一般最多一个，这个参数的有无和cmd的意义相关。 ioctl函数是文件结构中的一个属性分量，就是说如果你的驱动程序提供了对ioctl的支持，用户就可以在用户程序中使用ioctl函数来控制设备的I/O通道。

2、命令抓取方式 FILE* fp=NULL; char buf[100] = {0}; char command[300] = " sudo iwlist wlan0 scan"; char str1[100]; char str2[100]; char *q = NULL; memset(str1, '\0', sizeof(str1)); memset(str2, '\0', sizeof(str2)); if((fp = popen(command, "r")) != NULL) { // printf("popen command success\n"); while(fgets(buf, sizeof(buf), fp) != NULL) { //printf("buf=%s\n", buf); q = strstr(buf, "ESSID:"); if (q != NULL) { // printf("q =NULL\n"); sscanf(q, "ESSID:\"%[^\"]\"", str1); q = NULL; } q = strstr(buf, "Signal level="); if (q != NULL) { // printf("q =NULL\n"); sscanf(q, "Signal level=%[^/]", str2); q = NULL; strcat(str1,""); strcat(str1,str2); wifilist.append(str1); } } pclose(fp); }

popen将命令sudo iwlist wlan0 scan通过管道读到fp，fgets函数从指定的流中读取数据，每次读取一行。其原型为：

ioctl查询无线网卡信息 /* -------------------------- IOCTL LIST-------------------------- */ /* Basic operations */ #define SIOCSIWCOMMIT 0x8B00 /* 提交修改结果 */ #define SIOCGIWNAME 0x8B01 /* 获取设备名字 */ #define SIOCSIWNWID 0x8B02 /* 设置网络ID */ #define SIOCGIWNWID 0x8B03 /* 获取网络ID */ #define SIOCSIWFREQ 0x8B04 /* 设置信道（频率） */ #define SIOCGIWFREQ 0x8B05 /* 获取信道（频率） */ #define SIOCSIWMODE 0x8B06 /* 设置网卡模式*/ #define SIOCGIWMODE 0x8B07 /* 获取网卡模式 */ #define SIOCSIWSENS 0x8B08 /* 设置灵敏度(dBm) */ #define SIOCGIWSENS 0x8B09 /* 获取灵敏度 (dBm) */ /* Informative stuff */ #define SIOCSIWRANGE 0x8B0A /* Unused */ #define SIOCGIWRANGE 0x8B0B /* 获取参数范围 */ #define SIOCSIWPRIV 0x8B0C /* Unused */ #define SIOCGIWPRIV 0x8B0D /* 获取网卡特有的ioctl接口 */ #define SIOCSIWSTATS 0x8B0E /* Unused */ #define SIOCGIWSTATS 0x8B0F /* 获取 /proc/net/wireless的stats */ /* Mobile IP support */ #define SIOCSIWSPY 0x8B10 /* 设置spy 地址*/ #define SIOCGIWSPY 0x8B11 /* 获取spy信息（连接质量） */ /* Access Point manipulation */ #define SIOCSIWAP 0x8B14 /* 设置AP的mac地址 */ #define SIOCGIWAP 0x8B15 /* 获取AP的mac地址 */ #define SIOCGIWAPLIST 0x8B17 /* 获取周围Ap信息列表 */ #define SIOCSIWSCAN 0x8B18 /* 开始扫描 */ #define SIOCGIWSCAN 0x8B19 /* 获取扫描信息 */ /* 802.11 specific support */ #define SIOCSIWESSID 0x8B1A /* 设置ESSID */ #define SIOCGIWESSID 0x8B1B /* 获取ESSID */ #define SIOCSIWNICKN 0x8B1C /* 设置节点别名 */ #define SIOCGIWNICKN 0x8B1D /* 获取节点别名 */ /* As the ESSID and NICKN are strings upto 32 bytes long, it doesn't fit * within the 'iwreq' structure, sowe need to use the 'data' member to * point to a string in user space,like it is done for RANGE... * The "flags" memberindicate if the ESSID is active or not (promiscuous). */ /* Other parameters useful in 802.11 andsome other devices */ #define SIOCSIWRATE 0x8B20 /* 设置默认传输速率(bps) */ #define SIOCGIWRATE 0x8B21 /* 获取默认传输速率 (bps) */ #define SIOCSIWRTS 0x8B22 /* 设置 RTS/CTS 的临界值(bytes) */ #define SIOCGIWRTS 0x8B23 /* 获取 RTS/CTS 的临界值 (bytes) */ #define SIOCSIWFRAG 0x8B24 /* 设置分片传输的包大小 (bytes) */ #define SIOCGIWFRAG 0x8B25 /* 获取分片传输的包大小 (bytes)*/ #define SIOCSIWTXPOW 0x8B26 /* 设置传输功率 (dBm) */ #define SIOCGIWTXPOW 0x8B27 /* 获取传输功率(dBm) */ #define SIOCSIWRETRY 0x8B28 /* 设置重传次数和生存时间 */ #define SIOCGIWRETRY 0x8B29 /* 获取重传次数和生存时间 */ /* Encoding stuff (scrambling, hardwaresecurity, WEP...) */ #define SIOCSIWENCODE 0x8B2A /* 设置编码模式 */ #define SIOCGIWENCODE 0x8B2B /* 获取编码模式 */ /* Power saving stuff (power management,unicast and multicast) */ #define SIOCSIWPOWER 0x8B2C /* 设置电源管理模式 */ #define SIOCGIWPOWER 0x8B2D /* 获取电源管理模式*/ /* -------------------- DEV PRIVATE IOCTLLIST -------------------- */ /* These 16 ioctl are wireless deviceprivate. * Each driver is free to use themfor whatever purpose it chooses, * however the driver *must* exportthe description of those ioctls * with SIOCGIWPRIV and *must* usearguments as defined below. * If you don't follow those rules,DaveM is going to hate you (reason : * it make mixed 32/64bit operationimpossible). */ #define SIOCIWFIRSTPRIV 0x8BE0 #define SIOCIWLASTPRIV 0x8BFF /* Previously, we were usingSIOCDEVPRIVATE, but we now have our * separate range because ofcollisions with other tools such as * 'mii-tool'. * We now have 32 commands, so a bitmore space ;-). * Also, all 'odd' commands are onlyusable by root and don't return the * content of ifr/iwr to user (butyou are not obliged to use the set/get * convention, just use every othertwo command). * And I repeat : you are not obligedto use them with iwspy, but you * must be compliant with it. */ /* ------------------------- IOCTL STUFF------------------------- */ /* The first and the last (range) */ #define SIOCIWFIRST 0x8B00 #define SIOCIWLAST SIOCIWLASTPRIV /* 0x8BFF */

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