Use CSTD and remove local CSTD settings which are no longer needed.
[dragonfly.git] / lib / libstand / pager.c
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1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/lib/libstand/pager.c,v 1.4.2.1 2001/03/05 06:27:44 kris Exp $
1de703da 27 * $DragonFly: src/lib/libstand/pager.c,v 1.2 2003/06/17 04:26:51 dillon Exp $
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28 */
29/*
30 * Simple paged-output and paged-viewing functions
31 */
32
33#include "stand.h"
34#include <string.h>
35
36static int p_maxlines = -1;
37static int p_freelines;
38
39static char *pager_prompt1 = " --more-- <space> page down <enter> line down <q> quit ";
40static char *pager_blank = " ";
41
42/*
43 * 'open' the pager
44 */
45void
46pager_open(void)
47{
48 int nlines;
49 char *cp, *lp;
50
51 nlines = 24; /* sensible default */
52 if ((cp = getenv("LINES")) != NULL) {
53 nlines = strtol(cp, &lp, 0);
54 }
55
56 p_maxlines = nlines - 1;
57 if (p_maxlines < 1)
58 p_maxlines = 1;
59 p_freelines = p_maxlines;
60}
61
62/*
63 * 'close' the pager
64 */
65void
66pager_close(void)
67{
68 p_maxlines = -1;
69}
70
71/*
72 * Emit lines to the pager; may not return until the user
73 * has responded to the prompt.
74 *
75 * Will return nonzero if the user enters 'q' or 'Q' at the prompt.
76 *
77 * XXX note that this watches outgoing newlines (and eats them), but
78 * does not handle wrap detection (req. count of columns).
79 */
80
81int
82pager_output(const char *cp)
83{
84 int action;
85
86 if (cp == NULL)
87 return(0);
88
89 for (;;) {
90 if (*cp == 0)
91 return(0);
92
93 putchar(*cp); /* always emit character */
94
95 if (*(cp++) == '\n') { /* got a newline? */
96 p_freelines--;
97 if (p_freelines <= 0) {
98 printf("%s", pager_prompt1);
99 action = 0;
100 while (action == 0) {
101 switch(getchar()) {
102 case '\r':
103 case '\n':
104 p_freelines = 1;
105 action = 1;
106 break;
107 case ' ':
108 p_freelines = p_maxlines;
109 action = 1;
110 break;
111 case 'q':
112 case 'Q':
113 action = 2;
114 break;
115 default:
116 break;
117 }
118 }
119 printf("\r%s\r", pager_blank);
120 if (action == 2)
121 return(1);
122 }
123 }
124 }
125}
126
127/*
128 * Display from (fd).
129 */
130int
131pager_file(const char *fname)
132{
133 char buf[80];
134 size_t hmuch;
135 int fd;
136 int result;
137
138 if ((fd = open(fname, O_RDONLY)) == -1) {
139 printf("can't open '%s': %s\n", fname, strerror(errno));
140 return(-1);
141 }
142
143 for (;;) {
144 hmuch = read(fd, buf, sizeof(buf) - 1);
145 if (hmuch == -1) {
146 result = -1;
147 break;
148 }
149 if (hmuch == 0) {
150 result = 0;
151 break;
152 }
153 buf[hmuch] = 0;
154 if (pager_output(buf)) {
155 result = 1;
156 break;
157 }
158 }
159 close(fd);
160 return(result);
161}