source: MondoRescue/branches/2.2.5/mindi-busybox/util-linux/more.c

Last change on this file was 1765, checked in by Bruno Cornec, 16 years ago

Update to busybox 1.7.2
File size: 5.4 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 tarball for details.
15 */
16
17#include "libbb.h"
18#if ENABLE_FEATURE_USE_TERMIOS
19#include <termios.h>
20#endif /* FEATURE_USE_TERMIOS */
21
22
23#if ENABLE_FEATURE_USE_TERMIOS
24
25struct globals {
26 int cin_fileno;
27 struct termios initial_settings;
28 struct termios new_settings;
29};
30#define G (*(struct globals*)bb_common_bufsiz1)
31//#define G (*ptr_to_globals)
32#define INIT_G() ((void)0)
33//#define INIT_G() PTR_TO_GLOBALS = xzalloc(sizeof(G))
34#define initial_settings (G.initial_settings)
35#define new_settings (G.new_settings )
36#define cin_fileno (G.cin_fileno )
37
38#define setTermSettings(fd, argp) tcsetattr(fd, TCSANOW, argp)
39#define getTermSettings(fd, argp) tcgetattr(fd, argp)
40
41static void gotsig(int sig)
42{
43 putchar('\n');
44 setTermSettings(cin_fileno, &initial_settings);
45 exit(EXIT_FAILURE);
46}
47
48#else /* !FEATURE_USE_TERMIOS */
49#define INIT_G() ((void)0)
50#define setTermSettings(fd, argp) ((void)0)
51#endif /* FEATURE_USE_TERMIOS */
52
53#define CONVERTED_TAB_SIZE 8
54
55int more_main(int argc, char **argv);
56int more_main(int argc, char **argv)
57{
58 int c = c; /* for gcc */
59 int lines;
60 int input = 0;
61 int spaces = 0;
62 int please_display_more_prompt;
63 struct stat st;
64 FILE *file;
65 FILE *cin;
66 int len;
67 int terminal_width;
68 int terminal_height;
69
70 INIT_G();
71
72 argv++;
73 /* Another popular pager, most, detects when stdout
74 * is not a tty and turns into cat. This makes sense. */
75 if (!isatty(STDOUT_FILENO))
76 return bb_cat(argv);
77 cin = fopen(CURRENT_TTY, "r");
78 if (!cin)
79 return bb_cat(argv);
80
81#if ENABLE_FEATURE_USE_TERMIOS
82 cin_fileno = fileno(cin);
83 getTermSettings(cin_fileno, &initial_settings);
84 new_settings = initial_settings;
85 new_settings.c_lflag &= ~ICANON;
86 new_settings.c_lflag &= ~ECHO;
87 new_settings.c_cc[VMIN] = 1;
88 new_settings.c_cc[VTIME] = 0;
89 setTermSettings(cin_fileno, &new_settings);
90 signal(SIGINT, gotsig);
91 signal(SIGQUIT, gotsig);
92 signal(SIGTERM, gotsig);
93#endif
94
95 do {
96 file = stdin;
97 if (*argv) {
98 file = fopen_or_warn(*argv, "r");
99 if (!file)
100 continue;
101 }
102 st.st_size = 0;
103 fstat(fileno(file), &st);
104
105 please_display_more_prompt = 0;
106 /* never returns w, h <= 1 */
107 get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height);
108 terminal_height -= 1;
109
110 len = 0;
111 lines = 0;
112 while (spaces || (c = getc(file)) != EOF) {
113 int wrap;
114 if (spaces)
115 spaces--;
116 loop_top:
117 if (input != 'r' && please_display_more_prompt) {
118 len = printf("--More-- ");
119 if (st.st_size > 0) {
120 len += printf("(%d%% of %"OFF_FMT"d bytes)",
121 (int) (ftello(file)*100 / st.st_size),
122 st.st_size);
123 }
124 fflush(stdout);
125
126 /*
127 * We've just displayed the "--More--" prompt, so now we need
128 * to get input from the user.
129 */
130 for (;;) {
131 input = getc(cin);
132 input = tolower(input);
133#if !ENABLE_FEATURE_USE_TERMIOS
134 printf("\033[A"); /* up cursor */
135#endif
136 /* Erase the last message */
137 printf("\r%*s\r", len, "");
138
139 /* Due to various multibyte escape
140 * sequences, it's not ok to accept
141 * any input as a command to scroll
142 * the screen. We only allow known
143 * commands, else we show help msg. */
144 if (input == ' ' || input == '\n' || input == 'q' || input == 'r')
145 break;
146 len = printf("(Enter:next line Space:next page Q:quit R:show the rest)");
147 }
148 len = 0;
149 lines = 0;
150 please_display_more_prompt = 0;
151
152 if (input == 'q')
153 goto end;
154
155 /* The user may have resized the terminal.
156 * Re-read the dimensions. */
157#if ENABLE_FEATURE_USE_TERMIOS
158 get_terminal_width_height(cin_fileno, &terminal_width, &terminal_height);
159 terminal_height -= 1;
160#endif
161 }
162
163 /* Crudely convert tabs into spaces, which are
164 * a bajillion times easier to deal with. */
165 if (c == '\t') {
166 spaces = CONVERTED_TAB_SIZE - 1;
167 c = ' ';
168 }
169
170 /*
171 * There are two input streams to worry about here:
172 *
173 * c : the character we are reading from the file being "mored"
174 * input: a character received from the keyboard
175 *
176 * If we hit a newline in the _file_ stream, we want to test and
177 * see if any characters have been hit in the _input_ stream. This
178 * allows the user to quit while in the middle of a file.
179 */
180 wrap = (++len > terminal_width);
181 if (c == '\n' || wrap) {
182 /* Then outputting this character
183 * will move us to a new line. */
184 if (++lines >= terminal_height || input == '\n')
185 please_display_more_prompt = 1;
186 len = 0;
187 }
188 if (c != '\n' && wrap) {
189 /* Then outputting this will also put a character on
190 * the beginning of that new line. Thus we first want to
191 * display the prompt (if any), so we skip the putchar()
192 * and go back to the top of the loop, without reading
193 * a new character. */
194 goto loop_top;
195 }
196 /* My small mind cannot fathom backspaces and UTF-8 */
197 putchar(c);
198 }
199 fclose(file);
200 fflush(stdout);
201 } while (*argv && *++argv);
202 end:
203 setTermSettings(cin_fileno, &initial_settings);
204 return 0;
205}
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