host_serv.lc

unix网络编程卷1：套接口API的全书源码

/* include host_serv */
#include    "unp.h"##  1 ##src/lib/host_serv.c##

struct addrinfo *##  2 ##src/lib/host_serv.c##
host_serv(const char *host, const char *serv, int family, int socktype)##  3 ##src/lib/host_serv.c##
{##  4 ##src/lib/host_serv.c##
    int     n;##  5 ##src/lib/host_serv.c##
    struct addrinfo hints, *res;##  6 ##src/lib/host_serv.c##

    bzero(&hints, sizeof(struct addrinfo));##  7 ##src/lib/host_serv.c##
    hints.ai_flags = AI_CANONNAME;  /* always return canonical name */##  8 ##src/lib/host_serv.c##
    hints.ai_family = family;   /* AF_UNSPEC, AF_INET, AF_INET6, etc. */##  9 ##src/lib/host_serv.c##
    hints.ai_socktype = socktype;   /* 0, SOCK_STREAM, SOCK_DGRAM, etc. */## 10 ##src/lib/host_serv.c##

    if ((n = getaddrinfo(host, serv, &hints, &res)) != 0)## 11 ##src/lib/host_serv.c##
        return (NULL);## 12 ##src/lib/host_serv.c##

    return (res);               /* return pointer to first on linked list */## 13 ##src/lib/host_serv.c##
}## 14 ##src/lib/host_serv.c##
/* end host_serv */

/*## 15 ##src/lib/host_serv.c##
 * There is no easy way to pass back the integer return code from## 16 ##src/lib/host_serv.c##
 * getaddrinfo() in the function above, short of adding another argument## 17 ##src/lib/host_serv.c##
 * that is a pointer, so the easiest way to provide the wrapper function## 18 ##src/lib/host_serv.c##
 * is just to duplicate the simple function as we do here.## 19 ##src/lib/host_serv.c##
 */## 20 ##src/lib/host_serv.c##

struct addrinfo *## 21 ##src/lib/host_serv.c##
Host_serv(const char *host, const char *serv, int family, int socktype)## 22 ##src/lib/host_serv.c##
{## 23 ##src/lib/host_serv.c##
    int     n;## 24 ##src/lib/host_serv.c##
    struct addrinfo hints, *res;## 25 ##src/lib/host_serv.c##

    bzero(&hints, sizeof(struct addrinfo));## 26 ##src/lib/host_serv.c##
    hints.ai_flags = AI_CANONNAME;  /* always return canonical name */## 27 ##src/lib/host_serv.c##
    hints.ai_family = family;   /* 0, AF_INET, AF_INET6, etc. */## 28 ##src/lib/host_serv.c##
    hints.ai_socktype = socktype;   /* 0, SOCK_STREAM, SOCK_DGRAM, etc. */## 29 ##src/lib/host_serv.c##

    if ((n = getaddrinfo(host, serv, &hints, &res)) != 0)## 30 ##src/lib/host_serv.c##
        err_quit("host_serv error for %s, %s: %s",## 31 ##src/lib/host_serv.c##
                 (host == NULL) ? "(no hostname)" : host,## 32 ##src/lib/host_serv.c##
                 (serv == NULL) ? "(no service name)" : serv,## 33 ##src/lib/host_serv.c##
                 gai_strerror(n));## 34 ##src/lib/host_serv.c##

    return (res);               /* return pointer to first on linked list */## 35 ##src/lib/host_serv.c##
}## 36 ##src/lib/host_serv.c##