Thread: Working With Command Line Arguements

Code:

int main (int argc, char *argv[])

argv[0] is a null-terminated string of the name of your program (though what it actually contains can vary)
argv[1] is a null-terminated string of the first argument the user passed to your program
argv[2] is the second arg
argv[argc-1] is the last arg that was passed

..... and finally (to continue moi's help).... argv[argc] is a null pointer to provide a redundant check for the end of the list.

Have you looked at getopt() ?

something like:

Code:

#include <unistd.h>

int main(int argc, char **argv) {
    int opt;


    while((opt = getopt(argc, argv, "p:V")) != -1) {
      switch(opt) { 
        case 'p':
          printf("argument p = %s\n", optarg);
          break;
        case 'V':
          verbose++;
          break;
        case ':'
          printf("Option %c needs a value\n", opt);
          break;
        case '?':
          printf("invalid option?\n");
          break;
      }
    }
}

getopt(3)

Code:

#include <stdio.h>

void DefaultMessage ( void );

int main ( int argc, char * argv[] )  
{
	if (argc == 2)
	{
		if(argv[1][0] == '?')
		{
			printf("Help stuff would go here.\n");
		}
		else
		{
			printf("%s \n", argv[1]);
		}
	}
	else if ( argc >= 3 )
	{
		printf("Invalid input:\n");
		printf("Only one command-line parameter allowed.\n");
	}
	else
	{
		DefaultMessage();
	}
	return 0;
}

void DefaultMessage ( void )
{
	printf("CmdLine.exe:\n");
	printf("The purpose of this program is to demonstrate command line arguments.\n");
	printf("This program will print whatever you type on the screen.\n\n");
	printf("Example:\n");
	printf("C:\\>CmdLine.exe Hmmm\n");
	printf("Hmmm\n");
}