util-linux/more.c

   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) 1999-2003 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  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  22  * General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  27  *
  28  */
  29
  30 #include <stdio.h>
  31 #include <fcntl.h>
  32 #include <signal.h>
  33 #include <stdlib.h>
  34 #include <unistd.h>
  35 #include <sys/ioctl.h>
  36 #include "busybox.h"
  37
  38 static FILE *cin;
  39
  40 #ifdef CONFIG_FEATURE_USE_TERMIOS
  41 #include <termios.h>
  42 #define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
  43 #define getTermSettings(fd,argp) tcgetattr(fd, argp);
  44
  45 static struct termios initial_settings, new_settings;
  46
  47 static void set_tty_to_initial_mode(void)
  48 {
  49         setTermSettings(fileno(cin), &initial_settings);
  50 }
  51
  52 static void gotsig(int sig)
  53 {
  54         putchar('\n');
  55         exit(EXIT_FAILURE);
  56 }
  57 #endif /* CONFIG_FEATURE_USE_TERMIOS */
  58
  59
  60 static int terminal_width = 79; /* not 80 in case terminal has linefold bug */
  61 static int terminal_height = 24;
  62
  63
  64 extern int more_main(int argc, char **argv)
  65 {
  66         int c, lines, input = 0;
  67         int please_display_more_prompt = -1;
  68         struct stat st;
  69         FILE *file;
  70         int len, page_height;
  71
  72 #if defined CONFIG_FEATURE_AUTOWIDTH && defined CONFIG_FEATURE_USE_TERMIOS
  73         struct winsize win = { 0, 0, 0, 0 };
  74 #endif
  75
  76         argc--;
  77         argv++;
  78
  79
  80         /* not use inputing from terminal if usage: more > outfile */
  81         if(isatty(fileno(stdout))) {
  82                 cin = fopen(CURRENT_TTY, "r");
  83                 if (!cin)
  84                         cin = bb_xfopen(CONSOLE_DEV, "r");
  85                 please_display_more_prompt = 0;
  86 #ifdef CONFIG_FEATURE_USE_TERMIOS
  87                 getTermSettings(fileno(cin), &initial_settings);
  88                 new_settings = initial_settings;
  89                 new_settings.c_lflag &= ~ICANON;
  90                 new_settings.c_lflag &= ~ECHO;
  91 #ifndef linux
  92                 /* Hmm, in linux c_cc[] not parsed if set ~ICANON */
  93                 new_settings.c_cc[VMIN] = 1;
  94                 new_settings.c_cc[VTIME] = 0;
  95 #endif
  96                 setTermSettings(fileno(cin), &new_settings);
  97                 atexit(set_tty_to_initial_mode);
  98                 (void) signal(SIGINT, gotsig);
  99                 (void) signal(SIGQUIT, gotsig);
 100                 (void) signal(SIGTERM, gotsig);
 101 #endif
 102         }
 103
 104         do {
 105                 if (argc == 0) {
 106                         file = stdin;
 107                 } else
 108                         file = bb_wfopen(*argv, "r");
 109                 if(file==0)
 110                         goto loop;
 111
 112                 st.st_size = 0;
 113                 fstat(fileno(file), &st);
 114
 115                 if(please_display_more_prompt>0)
 116                         please_display_more_prompt = 0;
 117
 118 #if defined CONFIG_FEATURE_AUTOWIDTH && defined CONFIG_FEATURE_USE_TERMIOS
 119                 ioctl(fileno(stdout), TIOCGWINSZ, &win);
 120                 if (win.ws_row > 4)
 121                         terminal_height = win.ws_row - 2;
 122                 if (win.ws_col > 0)
 123                         terminal_width = win.ws_col - 1;
 124 #endif
 125                 len=0;
 126                 lines = 0;
 127                 page_height = terminal_height;
 128                 while ((c = getc(file)) != EOF) {
 129
 130                         if (please_display_more_prompt>0) {
 131                                 len = printf("--More-- ");
 132                                 if (file != stdin && st.st_size > 0) {
 133 #if _FILE_OFFSET_BITS == 64
 134                                         len += printf("(%d%% of %lld bytes)",
 135                                                    (int) (100 * ((double) ftell(file) /
 136                                                    (double) st.st_size)), (long long)st.st_size);
 137 #else
 138                                         len += printf("(%d%% of %ld bytes)",
 139                                                    (int) (100 * ((double) ftell(file) /
 140                                                    (double) st.st_size)), (long)st.st_size);
 141 #endif
 142                                 }
 143
 144                                 fflush(stdout);
 145
 146                                 /*
 147                                  * We've just displayed the "--More--" prompt, so now we need
 148                                  * to get input from the user.
 149                                  */
 150                                 input = getc(cin);
 151 #ifndef CONFIG_FEATURE_USE_TERMIOS
 152                                 printf("\033[A"); /* up cursor */
 153 #endif
 154                                 /* Erase the "More" message */
 155                                 putc('\r', stdout);
 156                                 while (--len >= 0)
 157                                         putc(' ', stdout);
 158                                 putc('\r', stdout);
 159                                 fflush(stdout);
 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                                         if(please_display_more_prompt==0)
 184                                         please_display_more_prompt = 1;
 185                                 /* Adjust the terminal height for any overlap, so that
 186                                  * no lines get lost off the top. */
 187                                 if (len >= terminal_width) {
 188                                         int quot, rem;
 189                                         quot = len / terminal_width;
 190                                         rem  = len - (quot * terminal_width);
 191                                         if (quot) {
 192                                                 if (rem)
 193                                                         page_height-=quot;
 194                                                 else
 195                                                         page_height-=(quot-1);
 196                                         }
 197                                 }
 198                                 if (++lines >= page_height) {
 199                                         if(please_display_more_prompt==0)
 200                                         please_display_more_prompt = 1;
 201                                 }
 202                                 len=0;
 203                         }
 204                         /*
 205                          * If we just read a newline from the file being 'mored' and any
 206                          * key other than a return is hit, scroll by one page
 207                          */
 208                         putc(c, stdout);
 209                         len++;
 210                 }
 211                 fclose(file);
 212                 fflush(stdout);
 213 loop:
 214                 argv++;
 215         } while (--argc > 0);
 216   end:
 217         return 0;
 218 }