IPC mechanism for telephone conversation using Unix domain sockets

I am implementing the IPC for a telephonic conversation.Created two files :receiver.c and caller.c.. The rc.h contains all the include files.I am testing out the use of Unix domain sockets according to FIFO's .. The caller.c file is :

#include "rc.h"
int main()
{
    int sock_fd;
    struct sockaddr_un unix_addr;
    char buf[2048];
    int n;
    if ((sock_fd=socket(AF_UNIX,SOCK_STREAM,0))<0)
    {
        perror("cli:socket()");
        exit(1);
    }
    unix_addr.sun_family=AF_UNIX;
    strcpy(unix_addr.sun_path,SERVER);
    if (connect(sock_fd,(struct sockaddr *) &unix_addr,
        sizeof(unix_addr.sun_family)+
        sizeof(unix_addr.sun_path))< 0)
    {
        perror("cli:connect()");
        exit(1);
    }
    sprintf(buf,"Reciever called by receiver");
    n=strlen(buf)+1;
    if (write (sock_fd,buf,n)!=n)
    {
        perror("cli:write()");
        exit(1);
    }
    printf("Caller sent-->%s",buf);
    if ((n=read(sock_fd,buf,2047))<0)
    {
        perror("cli:read()");
        exit(1);
    }
    buf[n]=0;
    while (buf[n]==0){n--;}
    if (buf[n]=='\n')
        buf[n]='\0';
    printf("Reciever received<--%s \n",buf);
    exit(0);
}

The receiver.c is:

#include <signal.h>
#include "rc.h"

static void stop(int n)
{
    unlink(SERVER);
    exit(0);
}

static void receiver()
{
    int sock_fd,cli_sock_fd;
    struct sockaddr_un unix_addr;
    char buf[2048];
    int n,addr_len;
    pid_t pid;
    char *pc;

    signal(SIGINT,stop);
    signal(SIGQUIT,stop);
    signal(SIGTERM,stop);
    unix_addr.sun_family=AF_UNIX;
    strcpy(unix_addr.sun_path,SERVER);
    addr_len=sizeof(unix_addr.sun_family)+strlen(unix_addr.sun_path);
    unlink(SERVER);
    if (bind(sock_fd,(struct sockaddr *)&unix_addr,addr_len)<0)
    {
        perror("Receiver:bind()");
        exit(1);
    }
    if (listen(sock_fd,5)<0)
    {
        perror("Receiver:caller()");
        unlink(SERVER);
        exit(1);
    }
    while ((cli_sock_fd=accept(sock_fd,(struct sockaddr*)&unix_addr,&addr_len))>=0)
    {
        if ((n=read(cli_sock_fd,buf,2047))<0)
        {
            perror("Receiver:read()");
            close(cli_sock_fd);
            continue;
        }
        buf[n]='\0';
        for(pc=buf;*pc!='\0' && (*pc<'0' || *pc>'9');pc++);
        pid=atol(pc);
        if (pid!=0)
        {
            sprintf(buf,"Receiver called by caller\n",pid);
            n=strlen(buf)+1;
            if (write(cli_sock_fd,buf,n)!=n)
                perror("Receiver:write()");
        }
        close(cli_sock_fd);
    }
    perror("Receiver:accept()");
    unlink(SERVER);
    exit(1);
}

int main()
{
    int r;
    if ((r=fork())==0)
        receiver();
    if(r<0)
    {
        perror("Receiver:fork()");
        exit(1);
    }
    exit(0);
}

Now the problem occurs while compiling where i am getting:

sourajyoti@ubuntu:~/os2$ gcc receiver.c -o test1
receiver.c: In function ‘stop’:
receiver.c:6:9: warning: unknown escape sequence: '\s' [enabled by default]
receiver.c: In function ‘receiver’:
receiver.c:23:28: warning: unknown escape sequence: '\s' [enabled by default]
receiver.c:25:9: warning: unknown escape sequence: '\s' [enabled by default]
receiver.c:34:10: warning: unknown escape sequence: '\s' [enabled by default]    
receiver.c:58:9: warning: unknown escape sequence: '\s' [enabled by default]

Then after this:

sourajyoti@ubuntu:~/os2$ ./test1
Receiver:bind(): Bad file descriptor

Same for client:

sourajyoti@ubuntu:~/os2$ gcc caller.c -o test2    
caller.c: In function ‘main’:    
caller.c:15:28: warning: unknown escape sequence: '\s' [enabled by default]    
sourajyoti@ubuntu:~/os2$ ./test2    
cli:connect(): No such file or directory

The header file rc.h is:

     #include <sys/types.h>
     #include <sys/socket.h>
     #include <sys/un.h>
     #include <sys/ipc.h>
     #include <sys/msg.h>
     #include <stdio.h>
     #include <errno.h>
     #include <stdlib.h>
     #include <unistd.h>
     #define SERVER "\tmp\server"

Copyright License：
Author:「Paku」,Reproduced under the CC 4.0 BY-SA copyright license with link to original source & disclaimer.
Link to：https://stackoverflow.com/questions/22491110/ipc-mechanism-for-telephone-conversation-using-unix-domain-sockets