ansi_c_pg34_ch01_e22.c

/*
 * Exercise 1-22.
 * Write a program to ``fold'' long input lines into two or more shorter lines
 * after the last non-blank character that occurs before the n-th column of
 * input. Make sure your program does something intelligent with very long
 * lines, and if there are no blanks or tabs before the specified column.
 */


# include <stdio.h>

#define	TABSTOP 8
#define LINESIZE 20
#define WORDSIZE	(3 * LINESIZE)



int
get_word(char *word, int lim) {
	int len = 0;
	int c;



	while (len < lim - 1 && (c = getchar()) != EOF) {
		if (c == ' ' || c == '\n' || c == '\t') {
			word[len++] = c;
			word[len] = '\0';
			return len;
		}
		word[len++] = c;
	}

	word[len] = '\0';
	return len;

}

int
main() {

	char word[WORDSIZE];
	int len;
	int offset = 0;
	int last;
	int i;
	int complete;

	while ((len = get_word(word, WORDSIZE)) != 0) {

		last = word[len - 1];

		/* can we just print the whole word in the current line*/
		if (offset + len <= LINESIZE - 1) {
			printf("%s",word);
			offset +=len;
			/* reset offset if it ends with '\n' */
			if (word[len - 1] == '\n') {
				offset = 0;
			}
		} else {
			/* shall we start new line now */
			if (LINESIZE - offset <= 1 ) {
				putchar ('\n');
				offset = 0;
			}
			/* print the word */
			for (i = 0; i < len; i++) {

				/*
				 * when we are close to the end of th line and there are still
				 * few characters left, then we have no option but to hyphenate
				 * the word
				 */
				if (offset == LINESIZE - 2 && (len -i -1) > 2) {
					putchar('-');
					putchar('\n');
					offset = 0;
				}

				putchar(word[i]);
				offset++;
			}

			/* if the word ends with '\n', then reset offset */
			if (word[i - 1] == '\n') {
				offset = 0;
			}

		}

	}
	return (0);
}