more.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini more implementation for busybox
   4  *
   5  *
   6  * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
   7  *
   8  * Latest version blended together by Erik Andersen <andersen@lineo.com>,
   9  * based on the original more implementation by Bruce, and code from the
  10  * Debian boot-floppies team.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  20  * General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  25  *
  26  */
  27
  28 #include <stdio.h>
  29 #include <fcntl.h>
  30 #include <signal.h>
  31 #include <stdlib.h>
  32 #include <sys/ioctl.h>
  33 #include "busybox.h"
  34
  35 /* ED: sparc termios is broken: revert back to old termio handling. */
  36 #ifdef BB_FEATURE_USE_TERMIOS
  37 #       if #cpu(sparc)
  38 #               include <termio.h>
  39 #               define termios termio
  40 #               define setTermSettings(fd,argp) ioctl(fd,TCSETAF,argp)
  41 #               define getTermSettings(fd,argp) ioctl(fd,TCGETA,argp)
  42 #       else
  43 #               include <termios.h>
  44 #               define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
  45 #               define getTermSettings(fd,argp) tcgetattr(fd, argp);
  46 #       endif
  47
  48 static FILE *cin;
  49
  50 static struct termios initial_settings, new_settings;
  51
  52 static void gotsig(int sig)
  53 {
  54         setTermSettings(fileno(cin), &initial_settings);
  55         putchar('\n');
  56         exit(EXIT_FAILURE);
  57 }
  58 #endif /* BB_FEATURE_USE_TERMIOS */
  59
  60
  61 static int terminal_width = 79; /* not 80 in case terminal has linefold bug */
  62 static int terminal_height = 24;
  63
  64
  65 extern int more_main(int argc, char **argv)
  66 {
  67         int c, lines, input = 0;
  68         int please_display_more_prompt;
  69         struct stat st;
  70         FILE *file;
  71         int len, page_height;
  72
  73 #if defined BB_FEATURE_AUTOWIDTH && defined BB_FEATURE_USE_TERMIOS
  74         struct winsize win = { 0, 0, 0, 0 };
  75 #endif
  76
  77         argc--;
  78         argv++;
  79
  80         do {
  81                 if (argc == 0) {
  82                         file = stdin;
  83                 } else
  84                         file = xfopen(*argv, "r");
  85
  86                 fstat(fileno(file), &st);
  87
  88 #ifdef BB_FEATURE_USE_TERMIOS
  89                 cin = fopen("/dev/tty", "r");
  90                 if (!cin)
  91                         cin = xfopen("/dev/console", "r");
  92                 getTermSettings(fileno(cin), &initial_settings);
  93                 new_settings = initial_settings;
  94                 new_settings.c_cc[VMIN] = 1;
  95                 new_settings.c_cc[VTIME] = 0;
  96                 new_settings.c_lflag &= ~ICANON;
  97                 new_settings.c_lflag &= ~ECHO;
  98                 setTermSettings(fileno(cin), &new_settings);
  99
 100 #       ifdef BB_FEATURE_AUTOWIDTH
 101                 ioctl(fileno(stdout), TIOCGWINSZ, &win);
 102                 if (win.ws_row > 4)
 103                         terminal_height = win.ws_row - 2;
 104                 if (win.ws_col > 0)
 105                         terminal_width = win.ws_col - 1;
 106 #       endif
 107
 108                 (void) signal(SIGINT, gotsig);
 109                 (void) signal(SIGQUIT, gotsig);
 110                 (void) signal(SIGTERM, gotsig);
 111
 112 #endif
 113                 len=0;
 114                 lines = 0;
 115                 page_height = terminal_height;
 116                 please_display_more_prompt = 0;
 117                 while ((c = getc(file)) != EOF) {
 118
 119                         if (please_display_more_prompt) {
 120                                 len = printf("--More-- ");
 121                                 if (file != stdin) {
 122 #if _FILE_OFFSET_BITS == 64
 123                                         len += printf("(%d%% of %lld bytes)",
 124                                                    (int) (100 * ((double) ftell(file) /
 125                                                    (double) st.st_size)), (long long)st.st_size);
 126 #else
 127                                         len += printf("(%d%% of %ld bytes)",
 128                                                    (int) (100 * ((double) ftell(file) /
 129                                                    (double) st.st_size)), (long)st.st_size);
 130 #endif
 131                                 }
 132                                 len += printf("%s",
 133 #ifdef BB_FEATURE_USE_TERMIOS
 134                                                            ""
 135 #else
 136                                                            "\n"
 137 #endif
 138                                         );
 139
 140                                 fflush(stdout);
 141
 142                                 /*
 143                                  * We've just displayed the "--More--" prompt, so now we need
 144                                  * to get input from the user.
 145                                  */
 146 #ifdef BB_FEATURE_USE_TERMIOS
 147                                 input = getc(cin);
 148 #else
 149                                 input = getc(stdin);
 150 #endif
 151
 152 #ifdef BB_FEATURE_USE_TERMIOS
 153                                 /* Erase the "More" message */
 154                                 putc('\r', stdout);
 155                                 while (--len >= 0)
 156                                         putc(' ', stdout);
 157                                 putc('\r', stdout);
 158                                 fflush(stdout);
 159 #endif
 160                                 len=0;
 161                                 lines = 0;
 162                                 page_height = terminal_height;
 163                                 please_display_more_prompt = 0;
 164
 165                                 if (input == 'q')
 166                                         goto end;
 167                         }
 168
 169                         /*
 170                          * There are two input streams to worry about here:
 171                          *
 172                          * c     : the character we are reading from the file being "mored"
 173                          * input : a character received from the keyboard
 174                          *
 175                          * If we hit a newline in the _file_ stream, we want to test and
 176                          * see if any characters have been hit in the _input_ stream. This
 177                          * allows the user to quit while in the middle of a file.
 178                          */
 179                         if (c == '\n') {
 180                                 /* increment by just one line if we are at
 181                                  * the end of this line */
 182                                 if (input == '\n')
 183                                         please_display_more_prompt = 1;
 184                                 /* Adjust the terminal height for any overlap, so that
 185                                  * no lines get lost off the top. */
 186                                 if (len >= terminal_width) {
 187                                         div_t result = div( len, terminal_width);
 188                                         if (result.quot) {
 189                                                 if (result.rem)
 190                                                         page_height-=result.quot;
 191                                                 else
 192                                                         page_height-=(result.quot-1);
 193                                         }
 194                                 }
 195                                 if (++lines >= page_height) {
 196                                         please_display_more_prompt = 1;
 197                                 }
 198                                 len=0;
 199                         }
 200                         /*
 201                          * If we just read a newline from the file being 'mored' and any
 202                          * key other than a return is hit, scroll by one page
 203                          */
 204                         putc(c, stdout);
 205                         len++;
 206                 }
 207                 fclose(file);
 208                 fflush(stdout);
 209
 210                 argv++;
 211         } while (--argc > 0);
 212   end:
 213 #ifdef BB_FEATURE_USE_TERMIOS
 214         setTermSettings(fileno(cin), &initial_settings);
 215 #endif
 216         return 0;
 217 }