Question

I am working only in C regarding this issue.

I have two function prototypes :

int pkg_permserver(const char *service, const char *protocol, int backlog, void (*errlog) (char *msg))

int pkg_permserver_ip(const char *ipOrHostname, const char *service, const char *protocol, int backlog, void (*errlog)(char *msg))

and the following segment of code :

int test_permserv(char *port) {
    int return_val;
    int num_port;
    char *chr_port;
    int nr_test_passed=0;
    chr_port = (char *) bu_malloc(8 * sizeof( char), "port string");

    printf("TESTING  PKG_PERMSERVER.....\n PORT PARAMETER TEST: \n");

    printf("TESTING VALID PORT...\n");
    return_val = pkg_permserver(port ,"tcp", 0, 0);
    display(return_val,1,&nr_test_passed);

    printf("TESTING INVALID PORT...\n");
    num_port = -1;
    sprintf(chr_port, "%d", num_port);
    return_val = pkg_permserver(chr_port ,"tcp", 0, 0);
    display(return_val,0,&nr_test_passed);
}

I am writing a test unit. I need to test each case ( valid / invalid ) for each parameter of a function.

I cannot modify the functions stated above. pkg_permserver and pkg_permserver_ip have the exact same parameters, except pkg_permserver_ip has the IpOrHostname additionally.

if I will write another function “test_permserver_ip” I do not want to copy – paste the part from test_permserver ( because the parameters are identical ).

What I have on my mind is something like int test_permserver(char * port, int which_function);

I want to avoid copying the same code for test_permserver_ip ( for the parameters that are identical to test_permserver ones)
The testing function for pkg_permserver_ip hasn’t been written yet.

This is the code for the two above functions :

int pkg_permserver(const char *service, const char *protocol, int backlog, void (*errlog) (char *msg))
{
    struct in_addr iface;
    iface.s_addr = INADDR_ANY;
    return _pkg_permserver_impl(iface, service, protocol, backlog, errlog);
}


int
pkg_permserver_ip(const char *ipOrHostname, const char *service, const char *protocol, int backlog, void (*errlog)(char *msg))
{
    struct hostent* host;
    struct in_addr iface;
    /* if ipOrHostname starts with a number, it's an IP */
    if (ipOrHostname) {
    if (ipOrHostname[0] >= '0' && ipOrHostname[0] <= '9') {
        iface.s_addr = inet_addr(ipOrHostname);
    } else {
        /* XXX gethostbyname is deprecated on Windows */
        host = gethostbyname(ipOrHostname);
        iface = *(struct in_addr*)host->h_addr;
    }
    return _pkg_permserver_impl(iface, service, protocol, backlog, errlog);
    } else {
    _pkg_perror(errlog, "pkg: ipOrHostname cannot be NULL");
    return -1;
    }
}

Answer 1

As ATaylor says, just extract the common stuff from both functions and get something like

int common_stuff_for_permserver(... all common params ...)
{
  ....
}

int pkg_permserver(...)
{
      /// nothing to add here
      return common_stuff_for_permserver( ... all params ... );
}

int pkg_permserver_ip(...)
{
      /// check for errors from common stuff
      if(!common_stuff_for_permserver( ... all params ... )) { return 0; }

      /// ip-specific stuff
      ...
}

If you don’t know how to extract the common part, post some more code for both functions and we’ll think it over.