Thread: main () command line arguments

Hey everyone. I'm a student at NIU and am looking for a little help to start me off on my first assignment. I just recently changed to a comp sci major, and am new to C++, but I have taken a course in C a few years back under my old major. Anyway, here's my question:

For my assignments, I'm supposed to read in 2 filenames from a command line. My teacher gave me the syntax for the main() function as:

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

I understand that argc is the number of arguments. The command line I will be entering is:

programname lines.dat township.dat

First, will argc = 2 or will argc = 3, and therefore will the
char *argv[] look like this:

argv[0] = programname or this argv[0] = lines.dat
argv[1] = lines.dat argv[1] = township.dat
argv[2] = township.dat

Also, when I enter the above command line, does argc automatically get set to 2 or 3, and does argv get set to one of the two assignments i wrote above, or do I have to code that into the program.

I am programing in UNIX, v. 5.8 and and using the g++ compiler.

Any help would be greatly appreciated to help me start off. Thanks for reading

Doesnt hurt to try and see what happens.

Compile this code and run progname something somethingelse and see what happens.

Code:

#include <iostream>
using namespace std;

int main(int argc, char *argv[])
{ 
	cout << "argc = " << argc << endl;
	for (int x=0; x < argc; x++)
		cout << "argv[" << x <<"] = " << argv[x] << endl;

  return  0;
}

Do a search before starting a new thread

This topic has been covered many times, also good luck with your c++-studies.