1 5dc21454 2023-07-14 jrmu /*
 2 5dc21454 2023-07-14 jrmu  * 1-21. Write a program entab that replaces strings of blanks by the minimum number of tabs and blanks to achieve the same spacing. Use the same tab stops as for detab. When either a tab or a single blank would suffice to reach a tab stop, which should be given preference?
 3 5dc21454 2023-07-14 jrmu  */
 4 5dc21454 2023-07-14 jrmu 
 5 5dc21454 2023-07-14 jrmu #include <stdio.h>
 6 5dc21454 2023-07-14 jrmu #define TABSTOP 8
 7 5dc21454 2023-07-14 jrmu 
 8 5dc21454 2023-07-14 jrmu main()
 9 5dc21454 2023-07-14 jrmu {
10 5dc21454 2023-07-14 jrmu 	int c, col, spaces;
11 5dc21454 2023-07-14 jrmu 
12 5dc21454 2023-07-14 jrmu 	for (col = 1, spaces = 0; (c = getchar())!=EOF; ++col) {
13 5dc21454 2023-07-14 jrmu 		if (c == ' ') {
14 5dc21454 2023-07-14 jrmu 			if (col%TABSTOP == 0) {
15 5dc21454 2023-07-14 jrmu 				printf ("\t");
16 5dc21454 2023-07-14 jrmu 				spaces = 0;
17 5dc21454 2023-07-14 jrmu 			} else {
18 5dc21454 2023-07-14 jrmu 				++spaces;
19 5dc21454 2023-07-14 jrmu 			}
20 5dc21454 2023-07-14 jrmu 		} else if (c == '\t') {
21 5dc21454 2023-07-14 jrmu 			do {
22 5dc21454 2023-07-14 jrmu 				printf(" ");
23 5dc21454 2023-07-14 jrmu 				++col;
24 5dc21454 2023-07-14 jrmu 			} while (col%TABSTOP != 1);
25 5dc21454 2023-07-14 jrmu 		} else {
26 5dc21454 2023-07-14 jrmu 			for (int i = 0; i < spaces; ++i) {
27 5dc21454 2023-07-14 jrmu 				printf(" ");
28 5dc21454 2023-07-14 jrmu 			}
29 5dc21454 2023-07-14 jrmu 			spaces = 0;
30 5dc21454 2023-07-14 jrmu 			printf("%c", c);
31 5dc21454 2023-07-14 jrmu 			if (c == '\n') {
32 5dc21454 2023-07-14 jrmu 				col = 0;
33 5dc21454 2023-07-14 jrmu 			}
34 5dc21454 2023-07-14 jrmu 		}
35 5dc21454 2023-07-14 jrmu 	}
36 5dc21454 2023-07-14 jrmu }