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) 1999-2004 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  * 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         FILE *in_file = stdin;
  71         int len, page_height;
  72
  73         argc--;
  74         argv++;
  75
  76
  77         /* not use inputing from terminal if usage: more > outfile */
  78         if(isatty(fileno(stdout))) {
  79                 cin = fopen(CURRENT_TTY, "r");
  80                 if (!cin)
  81                         cin = bb_xfopen(CONSOLE_DEV, "r");
  82                 in_file = cin;
  83                 please_display_more_prompt = 0;
  84 #ifdef CONFIG_FEATURE_USE_TERMIOS
  85                 getTermSettings(fileno(cin), &initial_settings);
  86                 new_settings = initial_settings;
  87                 new_settings.c_lflag &= ~ICANON;
  88                 new_settings.c_lflag &= ~ECHO;
  89                 new_settings.c_cc[VMIN] = 1;
  90                 new_settings.c_cc[VTIME] = 0;
  91                 setTermSettings(fileno(cin), &new_settings);
  92                 atexit(set_tty_to_initial_mode);
  93                 (void) signal(SIGINT, gotsig);
  94                 (void) signal(SIGQUIT, gotsig);
  95                 (void) signal(SIGTERM, gotsig);
  96 #endif
  97         }
  98
  99         do {
 100                 if (argc == 0) {
 101                         file = stdin;
 102                 } else
 103                         file = bb_wfopen(*argv, "r");
 104                 if(file==0)
 105                         goto loop;
 106
 107                 st.st_size = 0;
 108                 fstat(fileno(file), &st);
 109
 110                 if(please_display_more_prompt>0)
 111                         please_display_more_prompt = 0;
 112
 113                 get_terminal_width_height(fileno(in_file), &terminal_width, &terminal_height);
 114                 if (terminal_height > 4)
 115                         terminal_height -= 2;
 116                 if (terminal_width > 0)
 117                         terminal_width -= 1;
 118
 119                 len=0;
 120                 lines = 0;
 121                 page_height = terminal_height;
 122                 while ((c = getc(file)) != EOF) {
 123
 124                         if (please_display_more_prompt>0) {
 125                                 len = printf("--More-- ");
 126                                 if (file != stdin && st.st_size > 0) {
 127 #if _FILE_OFFSET_BITS == 64
 128                                         len += printf("(%d%% of %lld bytes)",
 129                                                    (int) (100 * ((double) ftell(file) /
 130                                                    (double) st.st_size)), (long long)st.st_size);
 131 #else
 132                                         len += printf("(%d%% of %ld bytes)",
 133                                                    (int) (100 * ((double) ftell(file) /
 134                                                    (double) st.st_size)), (long)st.st_size);
 135 #endif
 136                                 }
 137
 138                                 fflush(stdout);
 139
 140                                 /*
 141                                  * We've just displayed the "--More--" prompt, so now we need
 142                                  * to get input from the user.
 143                                  */
 144                                 input = getc(cin);
 145 #ifndef CONFIG_FEATURE_USE_TERMIOS
 146                                 printf("\033[A"); /* up cursor */
 147 #endif
 148                                 /* Erase the "More" message */
 149                                 putc('\r', stdout);
 150                                 while (--len >= 0)
 151                                         putc(' ', stdout);
 152                                 putc('\r', stdout);
 153                                 fflush(stdout);
 154                                 len=0;
 155                                 lines = 0;
 156                                 page_height = terminal_height;
 157                                 please_display_more_prompt = 0;
 158
 159                                 if (input == 'q')
 160                                         goto end;
 161                         }
 162
 163                         /*
 164                          * There are two input streams to worry about here:
 165                          *
 166                          * c     : the character we are reading from the file being "mored"
 167                          * input : a character received from the keyboard
 168                          *
 169                          * If we hit a newline in the _file_ stream, we want to test and
 170                          * see if any characters have been hit in the _input_ stream. This
 171                          * allows the user to quit while in the middle of a file.
 172                          */
 173                         if (c == '\n') {
 174                                 /* increment by just one line if we are at
 175                                  * the end of this line */
 176                                 if (input == '\n')
 177                                         if(please_display_more_prompt==0)
 178                                         please_display_more_prompt = 1;
 179                                 /* Adjust the terminal height for any overlap, so that
 180                                  * no lines get lost off the top. */
 181                                 if (len >= terminal_width) {
 182                                         int quot, rem;
 183                                         quot = len / terminal_width;
 184                                         rem  = len - (quot * terminal_width);
 185                                         if (quot) {
 186                                                 if (rem)
 187                                                         page_height-=quot;
 188                                                 else
 189                                                         page_height-=(quot-1);
 190                                         }
 191                                 }
 192                                 if (++lines >= page_height) {
 193                                         if(please_display_more_prompt==0)
 194                                         please_display_more_prompt = 1;
 195                                 }
 196                                 len=0;
 197                         }
 198                         /*
 199                          * If we just read a newline from the file being 'mored' and any
 200                          * key other than a return is hit, scroll by one page
 201                          */
 202                         putc(c, stdout);
 203                         len++;
 204                 }
 205                 fclose(file);
 206                 fflush(stdout);
 207 loop:
 208                 argv++;
 209         } while (--argc > 0);
 210   end:
 211         return 0;
 212 }