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

/* The C Programming Language: 2nd Edition
 *
 * Exercise 7-2: Write a program that will print arbitrary input in a sensible
 * way. As a minimum, it should print non-graphic characters in octal or
 * hexadecimal according to local custom, and break long text lines.
 *
 * Notes: I spent some time thinking about this one. I'm somewhat picky in how
 * I expect text to be handled, but the requirements are Spartan. Therefore, I
 * will provide a Spartan solution. :)
 *
 * Linux printf formats don't seem to allow for truncation of hex or octal,
 * so there wasn't an (easy, cat-zero friendly) way to work with the widths
 * produced by the format strings. However, the program compiles, it has
 * argument switches, it smartly breaks lines, and expands non-printable
 * characters. It does exactly what it's supposed to. :)
 */

#define MAXLINELEN 81
#define MAXBUF 102400

#define HEX 16
#define OCT 8

int fmt;

int mygetline(char s[], int max) {
	int c, i;
	i = 0;
	while (max-- > 0 && (c = getchar()) != EOF && c != '\n') {
		s[i++] = c;
	}
	if (c == '\n') {
		s[i++] = c;
	}
	s[i] = '\0';
	return i;
}

void fmt_print(char *s) {
	int i = 0;
	while (s[i] != '\0') {
		if (isprint(s[i]) || s[i] == '\n') {
			putchar(s[i]);
		} else {
			if (fmt == HEX) {
				printf("%4X", s[i]);
			} else {
				printf("%3o", s[i]);
			}
		}
		i++;
	}
}

void break_lines(char *s) {
	int fmt = HEX;
	int c, nl, space;
	for (c = 0, nl = 0, space = 0; s[c] != '\0'; c++) {
		/* The position of the last space */
		if (isspace(s[c])) {
			space = c;
		}
		/* Position of the last new line */
		if (s[c] == '\n') {
			nl = c;
		}
		if (c == (nl + MAXLINELEN - 1)) {
			if (space > nl) {
				s[space] = '\n';
				nl = space;
			}
		}
	}
}

void parse_args(int argc, char *argv[]) {
	int i;
	while (argc > 1) {
		--argc;
		if (argv[argc][0] == '-') {
			if (argv[argc][1] == 'o' && argv[argc][1] != '\0') {
				fmt = OCT;
			} else if (argv[argc][1] == 'h') {
				fmt = HEX;
			}
		}
	}
}

int main(int argc, char **argv) {
	char buffer[MAXBUF];
	parse_args(argc, argv);
	while (mygetline(buffer, MAXBUF)) {
		break_lines(buffer);
		fmt_print(buffer);
	}
}