/* 
 * Program to count how many times each character occurs in input file.
 * Filename given as command-line argument.
 */
#include <stdio.h>
#include <limits.h>
#include <ctype.h>

int main(int argc, char *argv[]) {
	if (argc != 2) {
		printf("arguments:  infile\n");
		return 1;
	}
	FILE * infile = fopen(argv[1], "r");
	if (infile == NULL) {
		printf("cannot open input\n");
		return 1;
	}

	int inchar;
	int count = 0;

	/* UCHAR_MAX defined in limits.h -- largest value for char */
	int counters[UCHAR_MAX+1] = { 0 };

	while ((inchar = fgetc(infile)) != EOF) {
		counters[inchar] += 1;
		count += 1;
	}
	printf("%d total chars\n", count);
	for (int ch = 0; ch <= UCHAR_MAX; ++ch) {
		if (isprint(ch)) {
			printf("char %c occurs %d times\n", 
				ch, counters[ch]);
		}
		else {
			printf("char with value %d occurs %d times\n", 
				ch, counters[ch]);
		}
	}

	fclose(infile);
	return 0;
}