#include <errno.h> /* maybe */
#include <fcntl.h> /* no */
#include <sysexits.h> /* sure */
#include <stdbool.h> /* no */
#include <stdio.h> /* yes */
#include <stdlib.h> /* yes */
#include <string.h> /* maybe */
#include <unistd.h> /* yes */
#define BUF_SIZE 4096

unsigned char u = 0; /* unbuffered */
unsigned char buf[BUF_SIZE];

void usage(char *argv0){
	fprintf(stderr, "Usage: %s (-u) (file...)\n", argv0);
	exit(EX_USAGE);
}

int main(int argc, char *argv[]) {
	char *argv0;
	extern int optind;
	int c;
	FILE *in;
	argv0 = argv[0];

	while ((c = getopt(argc, argv, "u")) != -1) {
			switch(c) {
					/*
					 * From cat(1p):
					 *
					 * -u        Write bytes from the input file to the standard output
					 *           without delay as each is read.
					 */
					case 'u':
						u = 1;
						break;
					default:
						usage(argv[0]);
			}
	}

	while(++argv != NULL) /* increments over argv[0] */
		/*
			 * From cat(1p):
			 *
			 * file      A pathname of an input file. If no file operands are
			 *           specified, the standard input shall be used. If a file is
			 *           '-', the cat utility shall read from the standard input at
			 *           that point in the sequence. The cat utility shall not close
			 *           and reopen standard input when it is referenced in this way,
			 *           but shall accept multiple occurrences of '-' as a file
			 *           operand.
			 */
	if(argv[0][0] == '-' && argv[0][1] == '\0') in = stdin;
					else if ((in = fopen(argv[0], "r")) == NULL) {
							// TODO: Add error handling
							usage(argv0);
							return EX_NOINPUT;
					}

					int byte = 0;
					char *buf = calloc(4096, 1);

					while ((c = fgetc(in) != EOF)) {
							if (u) {
									putchar(c);
							} else {
									/* fucky wucky buffering */
							}
					}

					if(!u) fputs(buf, stdout);

	        if(in != stdin) fclose(file); /* who cares if it cant close */
			}

			return EX_OK;
	}