source: MondoRescue/trunk/mindi-busybox/util-linux/more.c@ 954

/* vi: set sw=4 ts=4: */
/*
 * Mini more implementation for busybox
 *
 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Latest version blended together by Erik Andersen <andersen@codepoet.org>,
 * based on the original more implementation by Bruce, and code from the
 * Debian boot-floppies team.
 *
 * Termios corrects by Vladimir Oleynik <dzo@simtreas.ru>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <stdio.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include "busybox.h"


#ifdef CONFIG_FEATURE_USE_TERMIOS
static int cin_fileno;
#include <termios.h>
#define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
#define getTermSettings(fd,argp) tcgetattr(fd, argp);

static struct termios initial_settings, new_settings;

static void set_tty_to_initial_mode(void)
{
    setTermSettings(cin_fileno, &initial_settings);
}

static void gotsig(int sig)
{
    putchar('\n');
    exit(EXIT_FAILURE);
}
#endif /* CONFIG_FEATURE_USE_TERMIOS */


int more_main(int argc, char **argv)
{
    int c, lines, input = 0;
    int please_display_more_prompt = 0;
    struct stat st;
    FILE *file;
    FILE *cin;
    int len, page_height;
    int terminal_width;
    int terminal_height;

    argc--;
    argv++;


    /* not use inputing from terminal if usage: more > outfile */
    if(isatty(STDOUT_FILENO)) {
        cin = fopen(CURRENT_TTY, "r");
        if (!cin)
            cin = bb_xfopen(CONSOLE_DEV, "r");
        please_display_more_prompt = 2;
#ifdef CONFIG_FEATURE_USE_TERMIOS
        cin_fileno = fileno(cin);
        getTermSettings(cin_fileno, &initial_settings);
        new_settings = initial_settings;
        new_settings.c_lflag &= ~ICANON;
        new_settings.c_lflag &= ~ECHO;
        new_settings.c_cc[VMIN] = 1;
        new_settings.c_cc[VTIME] = 0;
        setTermSettings(cin_fileno, &new_settings);
        atexit(set_tty_to_initial_mode);
        (void) signal(SIGINT, gotsig);
        (void) signal(SIGQUIT, gotsig);
        (void) signal(SIGTERM, gotsig);
#endif
    } else {
        cin = stdin;
    }

    do {
        if (argc == 0) {
            file = stdin;
        } else
            file = bb_wfopen(*argv, "r");
        if(file==0)
            goto loop;

        st.st_size = 0;
        fstat(fileno(file), &st);

        please_display_more_prompt &= ~1;

        get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height);
        if (terminal_height > 4)
            terminal_height -= 2;
        if (terminal_width > 0)
            terminal_width -= 1;

        len=0;
        lines = 0;
        page_height = terminal_height;
        while ((c = getc(file)) != EOF) {

            if ((please_display_more_prompt & 3) == 3) {
                len = printf("--More-- ");
                if (file != stdin && st.st_size > 0) {
#if _FILE_OFFSET_BITS == 64
                    len += printf("(%d%% of %lld bytes)",
                           (int) (100 * ((double) ftell(file) /
                           (double) st.st_size)), (long long)st.st_size);
#else
                    len += printf("(%d%% of %ld bytes)",
                           (int) (100 * ((double) ftell(file) /
                           (double) st.st_size)), (long)st.st_size);
#endif
                }

                fflush(stdout);

                /*
                 * We've just displayed the "--More--" prompt, so now we need
                 * to get input from the user.
                 */
                input = getc(cin);
#ifndef CONFIG_FEATURE_USE_TERMIOS
                printf("\033[A"); /* up cursor */
#endif
                /* Erase the "More" message */
                putc('\r', stdout);
                while (--len >= 0)
                    putc(' ', stdout);
                putc('\r', stdout);
                len=0;
                lines = 0;
                page_height = terminal_height;
                please_display_more_prompt &= ~1;

                if (input == 'q')
                    goto end;
            }

            /*
             * There are two input streams to worry about here:
             *
             * c     : the character we are reading from the file being "mored"
             * input : a character received from the keyboard
             *
             * If we hit a newline in the _file_ stream, we want to test and
             * see if any characters have been hit in the _input_ stream. This
             * allows the user to quit while in the middle of a file.
             */
            if (c == '\n') {
                /* increment by just one line if we are at
                 * the end of this line */
                if (input == '\n')
                    please_display_more_prompt |= 1;
                /* Adjust the terminal height for any overlap, so that
                 * no lines get lost off the top. */
                if (len >= terminal_width) {
                    int quot, rem;
                    quot = len / terminal_width;
                    rem  = len - (quot * terminal_width);
                    if (quot) {
                        if (rem)
                            page_height-=quot;
                        else
                            page_height-=(quot-1);
                    }
                }
                if (++lines >= page_height) {
                    please_display_more_prompt |= 1;
                }
                len=0;
            }
            /*
             * If we just read a newline from the file being 'mored' and any
             * key other than a return is hit, scroll by one page
             */
            putc(c, stdout);
            len++;
        }
        fclose(file);
        fflush(stdout);
loop:
        argv++;
    } while (--argc > 0);
  end:
    return 0;
}