用strtok()来解析形如192.168.0.115:3333的IP地址。实现这个功能有两个关键点，一是对strtok()的正确使用，二是格式的转换。
#include #include #include #define IP_SZ 20 struct IPAddr { unsigned char ip[4]; unsigned short port; }; /*对形如192.168.0.115:3333的地址，先用":"，把地址分割成两段， 再用"."逐个分割。*/ int parserIP(const char* ip_str, struct IPAddr* aIPAddr) { char *bufIP, *bufPort, *bufIP0, *bufIP1, *bufIP2, *bufIP3; bufIP = strtok(ip_str, ":"); bufPort = strtok(NULL, ":"); bufIP0 = strtok(bufIP, "."); bufIP1 = strtok(NULL, "."); bufIP2 = strtok(NULL, "."); bufIP3 = strtok(NULL, "."); aIPAddr->ip[0] = (unsigned char)atoi(bufIP0); aIPAddr->ip[1] = (unsigned char)atoi(bufIP1); aIPAddr->ip[2] = (unsigned char)atoi(bufIP2); aIPAddr->ip[3] = (unsigned char)atoi(bufIP3); aIPAddr->port = atoi(bufPort); return 0; } /*改进的fgets()，删除末尾的'\n'*/ void Fgets(char *s, int n, FILE * stream) { fgets(s, n, stream); int len = strlen(s); s[len] = '\0'; } int main() { struct IPAddr IPAd; char buf[IP_SZ]; printf("input a IP address, like 192.168.0.112:2222\n"); Fgets(buf, IP_SZ, stdin); printf("get a IP address:%s\n", buf); parserIP(buf, &IPAd); printf("after parsering, the IP is:\n"); printf(" IPAd->ip[0]=%u\n IPAd->ip[1]=%u\n IPAd->ip[2]=%u\n IPAd->ip[3]=%u\n IPAd->port=%u\n", IPAd.ip[0], IPAd.ip[1], IPAd.ip[2], IPAd.ip[3], IPAd.port); return 0; }
某次的运行结果为：
