cliconn.c

unix环境高级编程的源代码

/* Create a client endpoint and connect to a server. */

#include    <sys/types.h>
#include    <sys/socket.h>
#include    <sys/stat.h>
#include    <sys/un.h>
#include    <stdio.h>
#include    <string.h>
#include    <unistd.h>
#include    "ourhdr.h"

#define    CLI_PATH    "/var/tmp/"        /* +5 for pid = 14 chars */
#define    CLI_PERM    S_IRWXU            /* rwx for user only */

int            /* returns fd if all OK, -1 on error */
cli_conn(const char *name)
{
    int                    fd, len;
    struct sockaddr_un    unix_addr;

                /* create a Unix domain stream socket */
    if ( (fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
        return(-1);

                /* fill socket address structure w/our address */
    memset(&unix_addr, 0, sizeof(unix_addr));
    unix_addr.sun_family = AF_UNIX;
    sprintf(unix_addr.sun_path, "%s%05d", CLI_PATH, getpid());
    len = /* th sizeof(unix_addr.sun_len) + */ sizeof(unix_addr.sun_family) +
          strlen(unix_addr.sun_path) /* th + 1 */;
    /* th unix_addr.sun_len = len; */
#ifdef    notdef
    if (len != 16)
        err_quit("length != 16");    /* hack */
#endif

    unlink(unix_addr.sun_path);        /* in case it already exists */
    if (bind(fd, (struct sockaddr *) &unix_addr, len) < 0)
        return(-1);
    if (chmod(unix_addr.sun_path, CLI_PERM) < 0)
        return(-1);

                /* fill socket address structure w/server's addr */
    memset(&unix_addr, 0, sizeof(unix_addr));
    unix_addr.sun_family = AF_UNIX;
    strcpy(unix_addr.sun_path, name);
    len = /* th sizeof(unix_addr.sun_len) + */ sizeof(unix_addr.sun_family) +
          strlen(unix_addr.sun_path) /* th + 1*/ ;
    /* th unix_addr.sun_len = len; */

    if (connect(fd, (struct sockaddr *) &unix_addr, len) < 0)
        return(-1);

    return(fd);
}