Unix下测试指定IP的端口是否开放
平时与不同业务之间联调的时候，经常得提前测试对方给的IP及端口是否开放着，Unix下用其它办法有点麻烦，索性用C语言自己写了一个程序。
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#include <stdio.h>#include <strings.h>#include <stdlib.h>#include <fcntl.h>#include <unistd.h>#include <sys/time.h>#include <sys/types.h>#include <sys/socket.h>//#include <arpa/inet.h>#include <netinet/in.h>#include <errno.h>#include <netdb.h>#define TIMEOUT 5/*FileName:testConn.cfunctions:test host:port which specified whether is alive.call:testConn hostname portreturn values:0 :connected.1:arguments err.2:port number illegal.3:gethostname err.4:network setup err.5:Connect server timeout.*///Build by cc at HPUX: cc -g -Wall testConn.c -o testConnint main(int argc, char **argv){ if(argc != 3) { printf("error:Usage: %s host port.\nExample: %s 192.168.0.1 21\n",argv[0],argv[0]); exit(1); } int portnumber=0; if ((portnumber = atoi (argv[2])) < 0) { fprintf (stderr, "error:port number[%s] is illegal.\n", argv[0]); exit (2); } struct hostent *host; if ((host = gethostbyname (argv[1])) == NULL) { fprintf (stderr, "error:Gethostname error\n"); exit (3); } int sockfd, flags, res; struct sockaddr_in servaddr; fd_set fdr, fdw; struct timeval timeout; sockfd = socket(AF_INET, SOCK_STREAM, 0); if(sockfd < 0) { perror("error:Netwrok error...\n"); return 4; } /* set socket fd noblock */ if((flags = fcntl(sockfd, F_GETFL, 0)) < 0) { perror("error:Netwrok error...\n"); close(sockfd); return 4; } if(fcntl(sockfd, F_SETFL, flags | O_NONBLOCK) < 0) { perror("error:Network error...\n"); close(sockfd); return 4; } bzero(&servaddr, sizeof(servaddr)); servaddr.sin_family = AF_INET; //inet_pton(AF_INET, argv[1], &servaddr.sin_addr); servaddr.sin_addr = *((struct in_addr *) host->h_addr); servaddr.sin_port = htons(portnumber); if(connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) != 0) { if(errno != EINPROGRESS) { // EINPROGRESS perror("error:Network err....\n"); close(sockfd); return 4; } } else { printf("Connected\n"); return 0; } FD_ZERO(&fdr); FD_ZERO(&fdw); FD_SET(sockfd, &fdr); FD_SET(sockfd, &fdw); timeout.tv_sec = TIMEOUT; timeout.tv_usec = 0; res = select(sockfd + 1, &fdr, &fdw, NULL, &timeout); if(res < 0) { perror("error:Network error...\n"); close(sockfd); return 4; } if(res == 0) { printf("error:Connect server timeout\n"); close(sockfd); return 5; } if(res == 1) { if(FD_ISSET(sockfd, &fdw)) { printf("Connected\n"); close(sockfd); return 0; } } /* Not necessary */ if(res == 2) { printf("error:Connect server timeout\n"); close(sockfd); return 5; } printf("error:Connect server timeout\n"); close(sockfd); return 5;}?