本文共 5419 字，大约阅读时间需要 18 分钟。
由于源代码注释几乎没有，可能新手较难看懂。因此鄙人加上了注释，有些小错误的地方也改了一下，其它不多说了。
程序1：检测接口的 inet_addr,netmask,broad_addr
程序2：检查接口的物理连接是否正常
程序3：更简单一点测试物理连接
程序4：调节音量
程序1：检测接口的 inet_addr,netmask,broad_addr
可能用到的资料：
1.ioctl和struct ifreq
上面链接中的源代码，头文件需要自己修改一下
//程序1：检测接口的 inet_addr,netmask,broad_addr #include#include #include #include #include #include #include #include #include #include #include static void usage(){ printf("usage : ipconfig interface\n"); exit(0); } int main(int argc,char **argv) { struct sockaddr_in *addr; //套接字地址结构体 struct ifreq ifr; //用于ioctl char *name, *address; //网络设备的名字，地址 int sockfd; //套接子描述符 if(argc != 2) //参数不够 usage(); else name = argv[1]; sockfd = socket(AF_INET, SOCK_DGRAM, 0); //打开一个数据流套接子 strncpy(ifr.ifr_name, name, IFNAMSIZ-1); //限制设备名的长度并截断，防止溢出 if(ioctl(sockfd, SIOCGIFADDR, &ifr) == -1) //用 SIOCGIFADDR 来获得接口地址 perror("ioctl error"), exit(1); //描述错误代码 addr = (struct sockaddr_in *)&(ifr.ifr_addr); address = inet_ntoa(addr->sin_addr); //地址转换 printf("inet addr: %s ",address); if(ioctl(sockfd, SIOCGIFBRDADDR, &ifr) == -1) //用 SIOCGIFBRDADDR 来获得广播地址 perror("ioctl error"),exit(1); addr = (struct sockaddr_in *)&ifr.ifr_broadaddr; address = inet_ntoa(addr->sin_addr); printf("broad addr: %s ",address); if(ioctl(sockfd, SIOCGIFNETMASK, &ifr) == -1) //用 SIOCGIFNETMASK 来获得掩码地址 perror("ioctl error"),exit(1); addr = (struct sockaddr_in *)&ifr.ifr_addr; address = inet_ntoa(addr->sin_addr); printf("inet mask: %s ",address); printf("\n"); exit(0); }
程序2：检查接口的物理连接是否正常
//程序2：检查接口的物理连接是否正常 #include#include #include #include #include #include #include #include #include #include typedef unsigned short u16; typedef unsigned int u32; typedef unsigned char u8; #include #include int detect_mii(int skfd, char *ifname) { struct ifreq ifr; u16 *data, mii_val; unsigned phy_id; //Get the vitals from the interface. strncpy(ifr.ifr_name, ifname, IFNAMSIZ); //MII=(媒介无关接口） //PHY=物理链路 if (ioctl(skfd, SIOCGMIIPHY, &ifr) < 0) { fprintf(stderr, "SIOCGMIIPHY on %s failed: %s\n", ifname, strerror(errno)); (void) close(skfd); return 2; } data = (u16 *)(&ifr.ifr_data); phy_id = data[0]; data[1] = 1; //REG regedit if (ioctl(skfd, SIOCGMIIREG, &ifr) < 0) { fprintf(stderr, "SIOCGMIIREG on %s failed: %s\n", ifr.ifr_name, strerror(errno)); return 2; } mii_val = data[3]; return(((mii_val & 0x0016) == 0x0004) ? 0 : 1); } int detect_ethtool(int skfd, char *ifname) { struct ifreq ifr; struct ethtool_value edata; memset(&ifr, 0, sizeof(ifr)); edata.cmd = ETHTOOL_GLINK; strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)-1); ifr.ifr_data = (char *) &edata; //ETH : EtherNet n. 以太网O /\tOOL 工具 if (ioctl(skfd, SIOCETHTOOL, &ifr) == -1) { printf("ETHTOOL_GLINK failed: %s\n", strerror(errno)); return 2; } return (edata.data ? 0 : 1); } int main(int argc, char **argv) { int skfd = -1; //套接子描述符 char *ifname; //接口设备名 int retval; //返回值 if( argv[1] ) ifname = argv[1]; else ifname = "eth0"; //默认值 //打开一个套接子 if (( skfd = socket( AF_INET, SOCK_DGRAM, 0 ) ) < 0 ) { printf("socket error\n"); exit(-1); } //探测以太网设备 retval = detect_ethtool(skfd, ifname); if (retval == 2)//上面失败情况下 //探测物理链路 retval = detect_mii(skfd, ifname); close(skfd); if (retval == 2) printf("Could not determine status\n"); if (retval == 1) printf("Link down\n"); if (retval == 0) printf("Link up\n"); return retval; }
程序3：更简单一点测试物理连接
//程序3：更简单一点测试物理连接 #include#include #include #include #include #include #include #define LINKTEST_GLINK 0x0000000a struct linktest_value { unsigned int cmd; unsigned int data; }; static void usage(const char * pname) { fprintf(stderr, "usage: %s \n", pname); fprintf(stderr, "returns: \n"); fprintf(stderr, "\t 0: link detected\n"); fprintf(stderr, "\t%d: %s\n", ENODEV, strerror(ENODEV)); fprintf(stderr, "\t%d: %s\n", ENONET, strerror(ENONET)); fprintf(stderr, "\t%d: %s\n", EOPNOTSUPP, strerror(EOPNOTSUPP)); exit(EXIT_FAILURE); } static int linktest(const char * devname) { struct ifreq ifr; struct linktest_value edata; int fd; // setup our control structures. memset(&ifr, 0, sizeof(ifr)); strcpy(ifr.ifr_name, devname);//为什么没有用strncpy了 //open control socket. fd = socket(AF_INET, SOCK_DGRAM, 0); if(fd < 0 ) { return -ECOMM; } errno = 0; edata.cmd = LINKTEST_GLINK; ifr.ifr_data = (caddr_t)&edata; if(!ioctl(fd, SIOCETHTOOL, &ifr)) { if(edata.data) { fprintf(stdout, "link detected on %s\n", devname); return 0; } else { errno=ENONET; } } perror("linktest"); return errno; } int main(int argc, char *argv[]) { if(argc != 2) { usage(argv[0]); } return linktest(argv[1]); }
程序4：调节音量
可能用到的资料：
Linux的混音设备/dev/mixer
//程序4：调节音量 #include#include #include #include #include #include #include #include #include #include #define BASE_VALUE 257 int main(int argc,char *argv[]) { int mixer_fd=0; char *names[SOUND_MIXER_NRDEVICES]=SOUND_DEVICE_LABELS; int value,i; //检查参数 if (argc<3) { printf("\nusage:%s dev_no.[0..24] value[0..100]\n\n",argv[0]); printf("eg. %s 0 100\n",argv[0]); printf(" will change the volume to MAX volume.\n\n"); printf("The dev_no. are as below:\n"); for (i=0; i
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