How to scp(transfer) file by a libssh?

Question

I am trying to transfer compiled executable file (compiled code c++, that prints 'Hello World!') to openssh linux server by using library libssh(I cant use terminal scp of openssh). I know, that libssh has a scp functions to transfer file from and to remoted ssh server. However there is some errors. This is a code of scp:

void ext(const char*c){
    std::cout<<c; 
    exit(-5); 
}
int scp_do(ssh_session session);
int scp_copy(ssh_session session, ssh_scp scp); 
int main(){
    int p = 22; 
    ssh_session session = ssh_new();
    if (session == NULL) 
      exit(-1);
    ssh_options_set(session, SSH_OPTIONS_HOST, "192.168.0.106");
    ssh_options_set(session, SSH_OPTIONS_PORT, &p);
    ssh_options_set(session, SSH_OPTIONS_USER, "user");
    int rc = ssh_connect(session);
    if (rc != SSH_OK){ //if not connected - exit
      ssh_disconnect(session);
      ext("Error connecting");
    }
    rc = ssh_userauth_password(session, NULL, "passwd");
    if(rc != SSH_AUTH_SUCCESS){ //if not authed - exit
      ssh_disconnect(session);
      ssh_free(session);
      return 0; 
    }

    scp_do(session); //copying file, main task of this code 

    ssh_disconnect(session);
    ssh_free(session);
    return 0 ; 
}
int scp_do(ssh_session session){ //copying file, main task of this code 
  ssh_scp scp;
  int rc;
  scp = ssh_scp_new(session, SSH_SCP_WRITE | SSH_SCP_RECURSIVE, ".");
  if (scp == NULL)
    ext("Error allocating scp session"); 
  rc = ssh_scp_init(scp);
  if (rc != SSH_OK)
    ext("Error initializing scp session"); 

  char buffer[1024]; 
  std::ifstream fin("hello"); // compiled executable file('hello world'), that I want to sent to server
  rc = ssh_scp_push_file(scp, "hello", 1024, S_IRUSR |  S_IWUSR); //creating server's file to copy there
  if (rc != SSH_OK)
    ext("Can't open remote file"); 
  fin.get(buffer, 1024); //reading from client's file
  rc = ssh_scp_write(scp, buffer, 1024); //copying all compiled code to server file
  if (rc != SSH_OK)
    ext("Can't write to remote file"); 
  ssh_scp_close(scp);
  ssh_scp_free(scp);
  return SSH_OK;
}

When I am trying to execute a transferred file on server, Firstly, I discover it is not executable. So I am doing chmod +x for file. Secondly, When i am executing file, I am getting error:

[1] 6867 segmentation fault ./hello However, when I am using scp of openssh to transfer file, there's no errors and it's executable. What can I do to solve my problems?

Answer 1

The size of file is like
4 62 17168 hello I was thinking it will be less 1024 bytes, bcs it's a just hello world). So, i need only to send 17168 bytes.