source: MondoRescue/branches/3.0/mindi-busybox/util-linux/more.c@ 3085

Last change on this file since 3085 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
File size: 5.3 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Mini more implementation for busybox
4 *
5 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
6 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 *
8 * Latest version blended together by Erik Andersen <andersen@codepoet.org>,
9 * based on the original more implementation by Bruce, and code from the
10 * Debian boot-floppies team.
11 *
12 * Termios corrects by Vladimir Oleynik <dzo@simtreas.ru>
13 *
14 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
15 */
16
17#include "libbb.h"
18
19/* Support for FEATURE_USE_TERMIOS */
20
21struct globals {
22 int cin_fileno;
23 struct termios initial_settings;
24 struct termios new_settings;
25} FIX_ALIASING;
26#define G (*(struct globals*)bb_common_bufsiz1)
27#define INIT_G() ((void)0)
28#define initial_settings (G.initial_settings)
29#define new_settings (G.new_settings )
30#define cin_fileno (G.cin_fileno )
31
32#define setTermSettings(fd, argp) \
33do { \
34 if (ENABLE_FEATURE_USE_TERMIOS) \
35 tcsetattr(fd, TCSANOW, argp); \
36} while (0)
37#define getTermSettings(fd, argp) tcgetattr(fd, argp)
38
39static void gotsig(int sig UNUSED_PARAM)
40{
41 /* bb_putchar_stderr doesn't use stdio buffering,
42 * therefore it is safe in signal handler */
43 bb_putchar_stderr('\n');
44 setTermSettings(cin_fileno, &initial_settings);
45 _exit(EXIT_FAILURE);
46}
47
48#define CONVERTED_TAB_SIZE 8
49
50int more_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
51int more_main(int argc UNUSED_PARAM, char **argv)
52{
53 int c = c; /* for compiler */
54 int lines;
55 int input = 0;
56 int spaces = 0;
57 int please_display_more_prompt;
58 struct stat st;
59 FILE *file;
60 FILE *cin;
61 int len;
62 unsigned terminal_width;
63 unsigned terminal_height;
64
65 INIT_G();
66
67 argv++;
68 /* Another popular pager, most, detects when stdout
69 * is not a tty and turns into cat. This makes sense. */
70 if (!isatty(STDOUT_FILENO))
71 return bb_cat(argv);
72 cin = fopen_for_read(CURRENT_TTY);
73 if (!cin)
74 return bb_cat(argv);
75
76 if (ENABLE_FEATURE_USE_TERMIOS) {
77 cin_fileno = fileno(cin);
78 getTermSettings(cin_fileno, &initial_settings);
79 new_settings = initial_settings;
80 new_settings.c_lflag &= ~ICANON;
81 new_settings.c_lflag &= ~ECHO;
82 new_settings.c_cc[VMIN] = 1;
83 new_settings.c_cc[VTIME] = 0;
84 setTermSettings(cin_fileno, &new_settings);
85 bb_signals(0
86 + (1 << SIGINT)
87 + (1 << SIGQUIT)
88 + (1 << SIGTERM)
89 , gotsig);
90 }
91
92 do {
93 file = stdin;
94 if (*argv) {
95 file = fopen_or_warn(*argv, "r");
96 if (!file)
97 continue;
98 }
99 st.st_size = 0;
100 fstat(fileno(file), &st);
101
102 please_display_more_prompt = 0;
103 /* never returns w, h <= 1 */
104 get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height);
105 terminal_height -= 1;
106
107 len = 0;
108 lines = 0;
109 while (spaces || (c = getc(file)) != EOF) {
110 int wrap;
111 if (spaces)
112 spaces--;
113 loop_top:
114 if (input != 'r' && please_display_more_prompt) {
115 len = printf("--More-- ");
116 if (st.st_size > 0) {
117 len += printf("(%u%% of %"OFF_FMT"u bytes)",
118 (int) (ftello(file)*100 / st.st_size),
119 st.st_size);
120 }
121 fflush_all();
122
123 /*
124 * We've just displayed the "--More--" prompt, so now we need
125 * to get input from the user.
126 */
127 for (;;) {
128 input = getc(cin);
129 input = tolower(input);
130 if (!ENABLE_FEATURE_USE_TERMIOS)
131 printf("\033[A"); /* cursor up */
132 /* Erase the last message */
133 printf("\r%*s\r", len, "");
134
135 /* Due to various multibyte escape
136 * sequences, it's not ok to accept
137 * any input as a command to scroll
138 * the screen. We only allow known
139 * commands, else we show help msg. */
140 if (input == ' ' || input == '\n' || input == 'q' || input == 'r')
141 break;
142 len = printf("(Enter:next line Space:next page Q:quit R:show the rest)");
143 }
144 len = 0;
145 lines = 0;
146 please_display_more_prompt = 0;
147
148 if (input == 'q')
149 goto end;
150
151 /* The user may have resized the terminal.
152 * Re-read the dimensions. */
153 if (ENABLE_FEATURE_USE_TERMIOS) {
154 get_terminal_width_height(cin_fileno, &terminal_width, &terminal_height);
155 terminal_height -= 1;
156 }
157 }
158
159 /* Crudely convert tabs into spaces, which are
160 * a bajillion times easier to deal with. */
161 if (c == '\t') {
162 spaces = CONVERTED_TAB_SIZE - 1;
163 c = ' ';
164 }
165
166 /*
167 * There are two input streams to worry about here:
168 *
169 * c : the character we are reading from the file being "mored"
170 * input: a character received from the keyboard
171 *
172 * If we hit a newline in the _file_ stream, we want to test and
173 * see if any characters have been hit in the _input_ stream. This
174 * allows the user to quit while in the middle of a file.
175 */
176 wrap = (++len > terminal_width);
177 if (c == '\n' || wrap) {
178 /* Then outputting this character
179 * will move us to a new line. */
180 if (++lines >= terminal_height || input == '\n')
181 please_display_more_prompt = 1;
182 len = 0;
183 }
184 if (c != '\n' && wrap) {
185 /* Then outputting this will also put a character on
186 * the beginning of that new line. Thus we first want to
187 * display the prompt (if any), so we skip the putchar()
188 * and go back to the top of the loop, without reading
189 * a new character. */
190 goto loop_top;
191 }
192 /* My small mind cannot fathom backspaces and UTF-8 */
193 putchar(c);
194 }
195 fclose(file);
196 fflush_all();
197 } while (*argv && *++argv);
198 end:
199 setTermSettings(cin_fileno, &initial_settings);
200 return 0;
201}
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