source: MondoRescue/branches/2.2.5/mindi-busybox/util-linux/more.c @ 1765

Last change on this file since 1765 was 1765, checked in by Bruno Cornec, 13 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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