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


void help (char * name)
{
	fprintf (stderr, "Usage:\n");
	fprintf (stderr, "     %s help\n", name);
	fprintf (stderr, "     %s <id>\n", name);
}


void die (void)
{
	fprintf (stderr, "Aborting\n");
	exit (1);
}


void usage (char * name)
{
	fprintf (stderr, "!!ERROR!! Wrong invocation\n");
	help (name);
	die ();
}


double parse_value (char * string)
{
	char * last;
	double value;

	value = strtod (string, &last);

	if (last == string) {
		fprintf (stderr, "Cannot parse value: `%s`\n", string);
		die ();
	} else if (last[0] != 0) {
		fprintf (stderr, "Partialy parsed value: `%s`\n", string);
		die ();
	}

	return (value);
}


void f1 (int argument_count, char * arguments[])
{
	char buff[10];
	memset(buff,0,sizeof(buff));
	strcpy(buff,"abcd");
	printf("buff = %s",&(*buff));
	exit (0);
}

void f2 (int argument_count, char * arguments[])
{
	int x = parse_value (arguments[1]);
	printf("Value = %d",x);
	exit (0);
}

void f3 (int argument_count, char * arguments[])
{
	unsigned sz = (unsigned)parse_value(arguments[1]);
	while (--sz >=0)
		printf("Value sz = %d",sz);
	exit (0);
}


void f4 (int argument_count, char * arguments[])
{
	int f;
	if (f == parse_value(arguments[1]))
	{
		f = parse_value(arguments[0]);
		printf("Value f = %d",f);
	}
	exit (0);

}


int main (int argc, char *argv[])
{
	if (argc < 2)
		usage (argv[0]);

	if (strcmp (argv[1], "help") == 0) {
		help (argv[0]);
		exit (0);
	} if (strcmp (argv[1], "1") == 0)
		f1 (argc, argv);
	else if (strcmp (argv[1], "2") == 0)
		f2 (argc, argv);
	else
		if (strcmp (argv[1], "3") == 0)
			f3 (argc, argv);
		else
			if (strcmp (argv[1], "3") == 0)
			f4 (argc, argv);
		usage (argv[0]);

	printf ("command not executed\n");
	die ();
}