C/C++ program template with one CLI argument

This example program provides an example of a CLI executable in C/C++ that uses one command line argument and exits with a usage message if that argument is not present:

#include <stdio.h>

int main(int argc, char **argv)
    if(argc <= 1) { // <= (number of expected CLI arguments)
        fprintf(stderr, "Usage: %s <input file>\n", argv[0]);
        return -1;
    // TODO Your code goes here!
    printf("Input file: %s\n", argv[1]);
    return 0;

Compile with

g++ -o cli-onearg cli-onearg.cpp

Usage example:

$ ./cli-onearg  
Usage: ./cli-onearg <input file>
$ ./cli-onearg my-input-file.txt
Input file: my-input-file.txt