1 /*
2  * 1-22. Write a program to "fold" long input lines into two or more shorter
3  * lines after the last non-blank character that occurs before the n-th
4  * column of input. Make sure your program does something intelligent with
5  * very long lines, and if there are no blanks or tabs before the specified
6  * column.
7  */
8 
9 #include <stdio.h>
10 #define WIDTH 80
11 #define TABSTOP 8
12 
13 int strln(char s[]);
14 void copy(char to[], char from[]);
15 
16 main()
17 {
18 	int c, i, ci;
19 	char current[WIDTH+1];
20 	int len;
21 
22 	ci = i = 0;
23 
24 	while ((c = getchar())!=EOF) {
25 		if (c == ' ') {
26 			current[ci] = '\0';
27 			len = strln(current)+1;
28 			if (i+len <= WIDTH) {
29 				printf("%s%c", current, c);
30 				i += len;
31 			} else {
32 				printf("\n%s%c", current, c);
33 				i = len;
34 			}
35 			ci = 0;
36 		} else if (c == '\n') {
37 			current[ci] = '\0';
38 			printf("%s%c", current, c);
39 			ci = i = 0;
40 		} else if (c == '\t') {
41 			len = strln(current)+TABSTOP;
42 			current[ci] = '\0';
43 			if (i+len <= WIDTH) {
44 				printf("%s%c", current, c);
45 				i += len;
46 			} else {
47 				printf("\n%s%c", current, c);
48 				i = len;
49 			}
50 			ci = 0;
51 		} else {
52 			len = strln(current)+1;
53 			if (i+len <= WIDTH) {
54 				current[ci] = c;
55 				++ci;
56 			} else {
57 				current[ci] = '\0';
58 				printf("%s\n%c", current, c);
59 				ci = 0;
60 				i = 1;
61 			}
62 		}
63 		current[ci] = '\0';
64 	}
65 }
66 int strln(char s[])
67 {
68 	int i;
69 	for (i=0; s[i] != '\0'; ++i)
70 		;
71 	return i;
72 }
73 void copy(char to[], char from[])
74 {
75 	int i;
76 	i = 0;
77 	while ((to[i] = from[i]) != '\0')
78 		++i;
79 }