root/socket/untelnet.c

DEFINITIONS

1. main

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>


int main(int argc, char *argv[])
{
        char c;
        FILE *fp;
        register int i, s, len;
        struct sockaddr_un saun;
        fd_set readset;
        int selres;
        char line[1024];
        if (argc!=2) {
                fprintf(stderr,"Usage: %s socketpath\n",argv[0]);
                exit(-5);
        }

        /*
         * Get a socket to work with.  This socket will
         * be in the UNIX domain, and will be a
         * stream socket.
         */
        if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
                perror("client: socket");
                exit(1);
        }

        /*
         * Create the address we will be connecting to.
         */
        saun.sun_family = AF_UNIX;
        strcpy(saun.sun_path, argv[1]);

        /*
         * Try to connect to the address.  For this to
         * succeed, the server must already have bound
         * this address, and must have issued a listen()
         * request.
         *
         * The third argument indicates the "length" of
         * the structure, not just the length of the
         * socket name.
         */
        len = sizeof(saun.sun_family) + strlen(saun.sun_path);

        if (connect(s, &saun, len) < 0) {
                perror("client: connect");
                exit(1);
        }

        /*fcntl(s,F_SETFL,O_NONBLOCK);*/
        FD_ZERO(&readset);
                FD_SET(0,&readset);
                FD_SET(s,&readset);
        while (selres=select(s+1,&readset,NULL,NULL,NULL)) {
                if (selres<0) {
                        perror("select");
                        return -2;
                }
                if (FD_ISSET(s,&readset)) {
                        len=read(s,line,1024);
                        if (len==0) return -1;
                        write(1,line,len);
                }
                if (FD_ISSET(0,&readset)) {
                        fgets(line,1024,stdin);
                        write(s,line,strnlen(line));
                }
                FD_ZERO(&readset);
                FD_SET(0,&readset);
                FD_SET(s,&readset);
                /*printf("selecting\n");*/
        }
        /*
         * We can simply use close() to terminate the
         * connection, since we're done with both sides.
         */
        close(s);

        exit(0);
}