c 2b 2b take command line arguments

1// command line arguments in c++ are stored in an array of c-strings
2// # of arguments: argc
3// actual arguments: argv
4
5#include <iostream>
6using namespace std;
7
8int main(int argc, char** argv){
9  for(int i = 0; i < argc; i++){
10    cout << "argv" << i << ": " << argv[i] << endl;
11  }
12  return 0;
13}
14
15/*
16
17./main.exe hello world
18
19argv0: main.exe
20argv1: hello
21argv2: world
22
23*/
24    

1#include <iostream>
2#include <cstdarg>
3using namespace std;
4
5double average(int num,...) {
6   va_list valist;               // A place to store the list of arguments (valist)
7   double sum = 0.0;
8   int i;
9   
10   va_start(valist, num);        // Initialize valist for num number of arguments
11   for (i = 0; i < num; i++) {   // Access all the arguments assigned to valist
12      sum += va_arg(valist, int);
13   }
14   va_end(valist);               // Clean memory reserved for valist
15   
16   return sum/num;
17}
18
19int main() {
20   cout << "[Average 3 numbers: 44,55,66] -> " << average(3, 44,55,66) << endl;
21   cout << "[Average 2 numbers: 10,11] -> " << average(2, 10,11) << endl; 
22   cout << "[Average 1 number:  18] -> " << average(1, 18) << endl; 
23}
24
25/*
26NOTE: You will need to use the following 'data_types' within the function
27va_list   :  A place to store the list of arguments (valist)
28va_start  :  Initialize valist for num number of arguments
29va_arg    :  Access all the arguments assigned to valist
30va_end    :  Clean memory reserved for valist
31*/

1// Use command lines
2
3int main(int argc, char *argv[])
4{
5
6	for(int i = 1; i < argc; i++){
7		if(!strcmp(argv[i], "-h") || !strcmp(argv[i], "--help") ){
8			printf("Usage: App <options>\nOptions are:\n");
9			printf("Option list goes here");
10			exit(0);
11		}else if(!strcmp(argv[i], "-c") || !strcmp(argv[i], "--custom")){
12			printf("argument accepted");
13		}else{
14			if(i == argc-1){
15				break;
16			}
17			MessageBox(NULL, TEXT("ERROR: Invalid Command Line Option Found: \"%s\".\n", argv[i]), TEXT("Error"), MB_ICONERROR | MB_OK);
18		}
19	}
20
21	MessageBox(NULL, TEXT("ERROR: No Command Line Option Found. Type in --hep or -h"), TEXT("Error"), MB_ICONERROR | MB_OK);
22}