daytimetcpcli1.lc

unix网络编程卷1：套接口API的全书源码

#include    "unp.h"##  1 ##src/names/daytimetcpcli1.c##

int##  2 ##src/names/daytimetcpcli1.c##
main(int argc, char **argv)##  3 ##src/names/daytimetcpcli1.c##
{##  4 ##src/names/daytimetcpcli1.c##
    int     sockfd, n;##  5 ##src/names/daytimetcpcli1.c##
    char    recvline[MAXLINE + 1];##  6 ##src/names/daytimetcpcli1.c##
    struct sockaddr_in servaddr;##  7 ##src/names/daytimetcpcli1.c##
    struct in_addr **pptr;##  8 ##src/names/daytimetcpcli1.c##
    struct in_addr *inetaddrp[2];##  9 ##src/names/daytimetcpcli1.c##
    struct in_addr inetaddr;## 10 ##src/names/daytimetcpcli1.c##
    struct hostent *hp;## 11 ##src/names/daytimetcpcli1.c##
    struct servent *sp;## 12 ##src/names/daytimetcpcli1.c##

    if (argc != 3)## 13 ##src/names/daytimetcpcli1.c##
        err_quit("usage: daytimetcpcli1 <hostname> <service>");## 14 ##src/names/daytimetcpcli1.c##

    if ((hp = gethostbyname(argv[1])) == NULL) {## 15 ##src/names/daytimetcpcli1.c##
        if (inet_aton(argv[1], &inetaddr) == 0) {## 16 ##src/names/daytimetcpcli1.c##
            err_quit("hostname error for %s: %s", argv[1],## 17 ##src/names/daytimetcpcli1.c##
                     hstrerror(h_errno));## 18 ##src/names/daytimetcpcli1.c##
        } else {## 19 ##src/names/daytimetcpcli1.c##
            inetaddrp[0] = &inetaddr;## 20 ##src/names/daytimetcpcli1.c##
            inetaddrp[1] = NULL;## 21 ##src/names/daytimetcpcli1.c##
            pptr = inetaddrp;## 22 ##src/names/daytimetcpcli1.c##
        }## 23 ##src/names/daytimetcpcli1.c##
    } else {## 24 ##src/names/daytimetcpcli1.c##
        pptr = (struct in_addr **) hp->h_addr_list;## 25 ##src/names/daytimetcpcli1.c##
    }## 26 ##src/names/daytimetcpcli1.c##

    if ((sp = getservbyname(argv[2], "tcp")) == NULL)## 27 ##src/names/daytimetcpcli1.c##
        err_quit("getservbyname error for %s", argv[2]);## 28 ##src/names/daytimetcpcli1.c##

    for (; *pptr != NULL; pptr++) {## 29 ##src/names/daytimetcpcli1.c##
        sockfd = Socket(AF_INET, SOCK_STREAM, 0);## 30 ##src/names/daytimetcpcli1.c##

        bzero(&servaddr, sizeof(servaddr));## 31 ##src/names/daytimetcpcli1.c##
        servaddr.sin_family = AF_INET;## 32 ##src/names/daytimetcpcli1.c##
        servaddr.sin_port = sp->s_port;## 33 ##src/names/daytimetcpcli1.c##
        memcpy(&servaddr.sin_addr, *pptr, sizeof(struct in_addr));## 34 ##src/names/daytimetcpcli1.c##
        printf("trying %s\n", Sock_ntop((SA *) &servaddr, sizeof(servaddr)));## 35 ##src/names/daytimetcpcli1.c##

        if (connect(sockfd, (SA *) &servaddr, sizeof(servaddr)) == 0)## 36 ##src/names/daytimetcpcli1.c##
            break;              /* success */## 37 ##src/names/daytimetcpcli1.c##
        err_ret("connect error");## 38 ##src/names/daytimetcpcli1.c##
        close(sockfd);## 39 ##src/names/daytimetcpcli1.c##
    }## 40 ##src/names/daytimetcpcli1.c##
    if (*pptr == NULL)## 41 ##src/names/daytimetcpcli1.c##
        err_quit("unable to connect");## 42 ##src/names/daytimetcpcli1.c##

    while ((n = Read(sockfd, recvline, MAXLINE)) > 0) {## 43 ##src/names/daytimetcpcli1.c##
        recvline[n] = 0;        /* null terminate */## 44 ##src/names/daytimetcpcli1.c##
        Fputs(recvline, stdout);## 45 ##src/names/daytimetcpcli1.c##
    }## 46 ##src/names/daytimetcpcli1.c##
    exit(0);## 47 ##src/names/daytimetcpcli1.c##
}## 48 ##src/names/daytimetcpcli1.c##