I have made little program for computing pi (p) as an integral. Now I am facing a question how to extend it to compute an integral, which will be given as an extra parameter when starting an application. How do I deal with such a parameter in a program?
This question is related to
c
Parsing command line arguments in a primitive way as explained in the above answers is reasonable as long as the number of parameters that you need to deal with is not too much.
I strongly suggest you to use an industrial strength library for handling the command line arguments.
This will make your code more professional.
Such a library for C++ is available in the following website. I have used this library in many of my projects, hence I can confidently say that this one of the easiest yet useful library for command line argument parsing. Besides, since it is just a template library, it is easier to import into your project. http://tclap.sourceforge.net/
A similar library is available for C as well. http://argtable.sourceforge.net/
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv) {
int i, parameter = 0;
if (argc >= 2) {
/* there is 1 parameter (or more) in the command line used */
/* argv[0] may point to the program name */
/* argv[1] points to the 1st parameter */
/* argv[argc] is NULL */
parameter = atoi(argv[1]); /* better to use strtol */
if (parameter > 0) {
for (i = 0; i < parameter; i++) printf("%d ", i);
} else {
fprintf(stderr, "Please use a positive integer.\n");
}
}
return 0;
}
There's also a C standard built-in library to get command line arguments: getopt
You can check it on Wikipedia or in Argument-parsing helpers for C/Unix.
Source: Stackoverflow.com