increment.c

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int main (int argc, char **argv) {
	char *str;
	long n;

	if (argc < 2) {
		printf ("Pass the number you want incremented.\n");
		return -1;
	}

	str = argv[1];
	n = strtol (str, (char **)NULL, 10);

	{
		char *tmp, *format;
		asprintf(&format, "%%%ss ", str);
		asprintf(&tmp, format, " ");
		n = strlen(tmp);
	}

	printf("number: %ld\n", n);

	return 0;
}