First Program

First program

hello.c

#include <stdio.h>

int main(void)
{
	printf("To C, or not to C: that is the question. \n");
	return 0;
}

• int: standard return type ➡️ void (return type not accepted by all the architectures)

• (void): explicit parameter (best-practice) ➡️ () implicit parameter (alternative)

hello.c (command line version)

#include <stdio.h>

int main(int argc, char *argv[])
{
	printf("To C, or not to C: that is the question. \n");
	return 0;
}

• argc: number of strings specified in command line

• argv: array of strings specifies in command line (separated by spaces)

Compilation

gcc hello.c -o hello

Execution

./hello

If you create the command line version of the code, you can specify several arguments. For example:

./hello arg1 arg2 ag3

• argc ➡️ 4

• argv ➡️ ["./hello", "arg1", "arg2", "arg3"]

Comments

// Single-line comment

/* Multi-line
   comment */