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getsopts.c

/*============================================================================    Name        : getsopts.c  Author      : Haier    Version     : 1.01    Copyright   : Copyright (c) 2014    Description : getsopts in C, Compile by Gcc    ============================================================================*/ #include <netinet/tcp.h>#include <sys/types.h>#include <sys/socket.h>#include <stdio.h>#include <unistd.h>#include <netinet/in.h>typedef union optval{intval;struct lingerlinger;struct timevaltv;unsigned char str[16];}val;typedef enum valtype{VALINT,VALLINGER,VALTIMEVAL,VALUCHAR,VALMAX}valtype;typedef struct sopts{int level;int optname;char *name;valtype valtype;}sopts;static val optval;sopts sockopts[] = {{SOL_SOCKET, SO_BROADCAST, "SO_BROADCAST", VALINT},{SOL_SOCKET, SO_DEBUG,   "SO_DEBUG",     VALINT},{SOL_SOCKET, SO_DONTROUTE, "SO_DONTROUTE", VALINT},{SOL_SOCKET, SO_ERROR,   "SO_ERROR",   VALINT},{SOL_SOCKET, SO_KEEPALIVE, "SO_KEEPALIVE", VALINT},{SOL_SOCKET, SO_LINGER,   "SO_LINGER",   VALINT},{SOL_SOCKET, SO_OOBINLINE, "SO_OOBINLINE", VALINT},{SOL_SOCKET, SO_RCVBUF,   "SO_RCVBUF",    VALINT},{SOL_SOCKET, SO_RCVLOWAT,  "SO_RCVLOWAT",  VALINT},{SOL_SOCKET, SO_RCVTIMEO,  "SO_RCVTIMEO",  VALTIMEVAL},{SOL_SOCKET, SO_SNDTIMEO,  "SO_SNDTIMEO",  VALTIMEVAL},{SOL_SOCKET, SO_TYPE,    "SO_TYPE",   VALINT},{IPPROTO_IP, IP_HDRINCL ,  "IP_HDRINCL",   VALINT},{IPPROTO_IP, IP_OPTIONS,   "IP_OPTIONS",   VALINT},{IPPROTO_IP, IP_TOS,   "IP_TOS",   VALINT},{IPPROTO_IP, IP_TTL,   "IP_TTL",   VALINT},{IPPROTO_IP, IP_MULTICAST_TTL, "IP_MULTICAST_TTL", VALUCHAR},{IPPROTO_IP, IP_MULTICAST_LOOP,"IP_MULTICAST_LOOP",VALUCHAR},{IPPROTO_TCP,TCP_KEEPCNT,  "TCP_KEEPCNT",  VALINT},{IPPROTO_TCP,TCP_MAXSEG,   "TCP_MAXSEG",   VALINT},{IPPROTO_TCP,TCP_NODELAY,  "TCP_NODELAY",  VALINT},{0, 0,   NULL,   VALMAX}};/*-------------------------------------------------------------------; 函数：display()---------------------------------------------------------------------*/static void display(sopts *sockopt, int len){switch(sockopt->valtype){case VALINT:{printf("optname %s: default is %d\n", sockopt->name, optval.val);break;}case VALLINGER:{printf("optname %s: default is %d\t%d to linger\n", sockopt->name, optval.linger.l_onoff, optval.linger.l_linger);break;}case VALTIMEVAL:{printf("optname %s: default is %.06f\n", sockopt->name, ((((double)optval.tv.tv_sec * 100000 + (double)optval.tv.tv_usec))/(double)1000000));break;}case VALUCHAR:{int i = 0;printf("optname %s: default is ", sockopt->name);for(i=0; i<len; i++){printf("%02x ", optval.str[i]);}printf("\n");break;}default:{break;}}}/*-------------------------------------------------------------------; 函数：main()---------------------------------------------------------------------*/int main(int argc, char *argv[]){int err = -1;socklen_t len = 0;int i = 0;int fd = socket(AF_INET, SOCK_STREAM, 0);while(sockopts[i++].valtype != VALMAX){len = sizeof(sopts);err = getsockopt(fd, sockopts->level, sockopts->optname, &optval, &len);if(err > -1){display(&sockopts[i], len);}}close(fd);return 0;}

运行示例：

[Lenovo@Linux Ping]$ ./sopts_get.o optname SO_BROADCAST: default is 0optname SO_DEBUG: default is 0optname SO_DONTROUTE: default is 0optname SO_ERROR: default is 0optname SO_KEEPALIVE: default is 0optname SO_LINGER: default is 0optname SO_OOBINLINE: default is 0optname SO_RCVBUF: default is 0optname SO_RCVLOWAT: default is 0optname SO_RCVTIMEO: default is 0.000000optname SO_SNDTIMEO: default is 0.000000optname SO_TYPE: default is 0optname IP_HDRINCL: default is 0optname IP_OPTIONS: default is 0optname IP_TOS: default is 0optname IP_TTL: default is 0optname IP_MULTICAST_TTL: default is 00 00 00 00 optname IP_MULTICAST_LOOP: default is 00 00 00 00 optname TCP_KEEPCNT: default is 0optname TCP_MAXSEG: default is 0optname TCP_NODELAY: default is 0