util-linux/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 "internal.h"
  29 #include <stdio.h>
  30 #include <fcntl.h>
  31 #include <signal.h>
  32 #include <sys/ioctl.h>
  33
  34 static const char more_usage[] = "more [file ...]\n";
  35
  36 #ifdef BB_FEATURE_USE_TERMIOS
  37
  38 #include <termio.h>
  39
  40 FILE *cin;
  41 /* sparc and other have broken termios support: use old termio handling. */
  42 struct termio initial_settings, new_settings;
  43
  44 void gotsig(int sig)
  45 {
  46         ioctl(fileno(cin), TCSETAF, &initial_settings);
  47         fprintf(stdout, "\n");
  48         exit(TRUE);
  49 }
  50 #endif
  51
  52
  53
  54 #define TERMINAL_WIDTH  79              /* not 80 in case terminal has linefold bug */
  55 #define TERMINAL_HEIGHT 24
  56
  57
  58 #if defined BB_FEATURE_AUTOWIDTH
  59 static int terminal_width = 0, terminal_height = 0;
  60 #else
  61 #define terminal_width  TERMINAL_WIDTH
  62 #define terminal_height TERMINAL_HEIGHT
  63 #endif
  64
  65
  66
  67 extern int more_main(int argc, char **argv)
  68 {
  69         int c, lines = 0, input = 0;
  70         int next_page = 0;
  71         struct stat st;
  72         FILE *file;
  73
  74 #ifdef BB_FEATURE_AUTOWIDTH
  75         struct winsize win = { 0, 0 };
  76 #endif
  77
  78         argc--;
  79         argv++;
  80
  81         if (argc > 0
  82                 && (strcmp(*argv, "--help") == 0 || strcmp(*argv, "-h") == 0)) {
  83                 usage(more_usage);
  84         }
  85         do {
  86                 if (argc == 0) {
  87                         file = stdin;
  88                 } else
  89                         file = fopen(*argv, "r");
  90
  91                 if (file == NULL) {
  92                         perror(*argv);
  93                         exit(FALSE);
  94                 }
  95                 fstat(fileno(file), &st);
  96
  97 #ifdef BB_FEATURE_USE_TERMIOS
  98                 cin = fopen("/dev/tty", "r");
  99                 if (!cin)
 100                         cin = fopen("/dev/console", "r");
 101                 ioctl(fileno(cin), TCGETA, &initial_settings);
 102                 new_settings = initial_settings;
 103                 new_settings.c_lflag &= ~ICANON;
 104                 new_settings.c_lflag &= ~ECHO;
 105                 ioctl(fileno(cin), TCSETAF, &new_settings);
 106
 107 #ifdef BB_FEATURE_AUTOWIDTH
 108                 ioctl(fileno(stdout), TIOCGWINSZ, &win);
 109                 if (win.ws_row > 4)
 110                         terminal_height = win.ws_row - 2;
 111                 if (win.ws_col > 0)
 112                         terminal_width = win.ws_col - 1;
 113 #endif
 114
 115                 (void) signal(SIGINT, gotsig);
 116                 (void) signal(SIGQUIT, gotsig);
 117                 (void) signal(SIGTERM, gotsig);
 118
 119 #endif
 120                 while ((c = getc(file)) != EOF) {
 121                         if (next_page) {
 122                                 int len = 0;
 123
 124                                 next_page = 0;
 125                                 lines = 0;
 126                                 len = fprintf(stdout, "--More-- ");
 127                                 if (file != stdin) {
 128                                         len += fprintf(stdout, "(%d%% of %ld bytes)",
 129                                                                    (int) (100 *
 130                                                                                   ((double) ftell(file) /
 131                                                                                    (double) st.st_size)),
 132                                                                    st.st_size);
 133                                 }
 134                                 len += fprintf(stdout, "%s",
 135 #ifdef BB_FEATURE_USE_TERMIOS
 136                                                            ""
 137 #else
 138                                                            "\n"
 139 #endif
 140                                         );
 141
 142                                 fflush(stdout);
 143                                 input = getc(cin);
 144
 145 #ifdef BB_FEATURE_USE_TERMIOS
 146                                 /* Erase the "More" message */
 147                                 while (--len >= 0)
 148                                         putc('\b', stdout);
 149                                 while (++len <= terminal_width)
 150                                         putc(' ', stdout);
 151                                 while (--len >= 0)
 152                                         putc('\b', stdout);
 153                                 fflush(stdout);
 154 #endif
 155
 156                         }
 157                         if (c == '\n') {
 158                                 switch (input) {
 159                                 case 'q':
 160                                         goto end;
 161                                 case '\n':
 162                                         /* increment by just one line if we are at
 163                                          * the end of this line*/
 164                                         next_page = 1;
 165                                         break;
 166                                 }
 167                                 if (++lines == terminal_height)
 168                                         next_page = 1;
 169                         }
 170                         putc(c, stdout);
 171                 }
 172                 fclose(file);
 173                 fflush(stdout);
 174
 175                 argv++;
 176         } while (--argc > 0);
 177   end:
 178 #ifdef BB_FEATURE_USE_TERMIOS
 179         gotsig(0);
 180 #endif
 181         exit(TRUE);
 182 }