#include <stdio.h>
#include <unistd.h>

int chc(FILE* fp)
{
    register int c;
    int num_chars = 0;
    while ((c = getc(fp)) != EOF) {
			num_chars ++;
    }
    printf("%i\n", num_chars);
    return 0;
}

int main(int argc, char** argv)
{
    if (argc == 1) {
        return chc(stdin);
    } else if (argc > 1) {
        FILE* fp = fopen(argv[1], "r");
        if (!fp) {
            perror("Could not open file");
            return 1;
        }
				return chc(fp) && fclose(fp);
    } else {
        printf("Usage: chc file.txt\n");
        printf("   or: cat file.txt | chc\n");
        printf("   or: chc # read from user-inputted stdin\n");
    }
    return 0;
}