xref: /original-bsd/contrib/ed/z.c (revision b4971bb3)
1 /*-
2  * Copyright (c) 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Rodney Ruddock of the University of Guelph.
7  *
8  * %sccs.include.redist.c%
9  */
10 
11 #ifndef lint
12 static char sccsid[] = "@(#)z.c	8.1 (Berkeley) 05/31/93";
13 #endif /* not lint */
14 
15 #include <sys/types.h>
16 
17 #include <regex.h>
18 #include <setjmp.h>
19 #include <stdio.h>
20 #include <string.h>
21 
22 #ifdef DBI
23 #include <db.h>
24 #endif
25 
26 #include "ed.h"
27 #include "extern.h"
28 
29 /*
30  * This prints out the next group of lines (as spec'd by the skicky
31  * number; 22 by default). It's really useful for scrolling in chunks
32  * through the buffer (better than l, n, or p). Shame on POSIX for
33  * not including it; yaaa! BSD for keeping it! :-)
34  */
35 void
36 z(inputt, errnum)
37 	FILE *inputt;
38 	int *errnum;
39 {
40 	register int l_cnt;
41 
42 	if (current == NULL) {
43 		*errnum = -1;
44 		strcpy(help_msg, "buffer empty");
45 		return;
46 	}
47 	/* Set zsnum if need be here. */
48 	ss = getc(inputt);
49 	if ((ss > 48) && (ss < 57))
50 		/* Default set in main. */
51 		zsnum = dig_num_conv(inputt, errnum);
52 	else
53 		if ((ss != '\n') && (ss != EOF)) {
54 			ungetc(ss, inputt);
55 			if (rol(inputt, errnum))
56 				return;
57 		}
58 	if (top == NULL) {
59 		strcpy(help_msg, "buffer empty");
60 		*errnum = -1;
61 		ungetc('\n', inputt);
62 		return;
63 	}
64 	if (End_default) {
65 		if ((current->below) != NULL)
66 			Start = current->below;
67 		else {
68 			strcpy(help_msg, "at end of buffer");
69 			*errnum = -1;
70 			ungetc('\n', inputt);
71 			return;
72 		}
73 	} else
74 		Start = End;
75 	if (Start == NULL) {
76 		strcpy(help_msg, "bad address");
77 		*errnum = -1;
78 		ungetc('\n', inputt);
79 		return;
80 	}
81 	Start_default = End_default = 0;
82 
83 	current = Start;
84 	l_cnt = 1;		/* Yes, set to = 1. */
85 	while (1) {
86 		/* Scroll-out the next 'zsnum' of lines or until bottom. */
87 		if (current == NULL)
88 			break;
89 		if (sigint_flag && (!sigspecial))
90 			SIGINT_ACTION;
91 		get_line(current->handle, current->len);
92 		printf("%s\n", text);
93 		if (current == bottom)
94 			break;
95 		l_cnt++;
96 		if (zsnum < l_cnt)
97 			break;
98 		current = current->below;
99 	}
100 	*errnum = 1;
101 }
102