Thread: Passing a parameter into the executable

I want to create 12 shortcuts that point to the same executable. I want the command line of these shortcuts to pass two variables into the program. I know how to do this using batch programs (%1 %2) but have never done this with a C executable. Can anyone point me in the right direction?

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

int main( void ) {
struct tm *tm_now;
time_t now = time(NULL);
int hour;
int min;
FILE *infile;

tm_now = localtime(&now);

tm_now->tm_min += 3; /* now add 3 minutes */
now = mktime( tm_now ); /* normalise the time */

tm_now = localtime(&now);

hour = tm_now->tm_hour;
min = tm_now->tm_min;

infile = fopen("atline.bat", "w");
fprintf(infile,"at \\\\TWPC-BELL-DC01 %d:%d c:\\securedox\\send\\fileprep 1 1\n", hour, min);
fprintf(infile,"net send \\\\TWPC-BELL-WS02 The file will be sent at %d:%d", hour, min);
fclose(infile);

system("atline");

return EXIT_SUCCESS;
}

This is my program, I'm going to want to receive two integers from the execution (1-12). I'd have "program 1 2". I want to take the "1" and store it as a variable and the "2" stored as another variable. Thanks in advance for any help!

Sarah

You declare it like this:

int main (int argc, char ** argv)

then, your program's name is stored as argv[0].
The first parameter is argv[1], the next argv[2], etc.

argc tells how many parameters are passed, COUNTING the program name. So, if you pass 2 parameters like you want, argc will be 3 (but you should check for this, and print an error message if the user gives too many/too few params). argv[0], argv[1], and argv[2] will be strings (char *'s) to these parameters.

To get an integer numeric input, use the atoi function, like this:

Code:

int main(int argc, char ** argv){
	int param1, param2;
	//other variables
	if (argc < 3){
		printf("Too few parameters!");
		exit(1);
	}
	if(argc > 3){
		printf("Too many parameters!");
		exit(1);
	}
	//Ok, we have the right # of params:
	param1 = atoi(argv[1]);
	param2 = atoi(argv[2]);
	//Rest of the code here
}