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 #define BB_DECLARE_EXTERN
  34 #define bb_need_help
  35 #include "messages.c"
  36
  37 static const char more_usage[] = "more [FILE ...]\n"
  38 #ifndef BB_FEATURE_TRIVIAL_HELP
  39         "\nMore is a filter for viewing FILE one screenful at a time.\n"
  40 #endif
  41         ;
  42
  43 /* ED: sparc termios is broken: revert back to old termio handling. */
  44 #ifdef BB_FEATURE_USE_TERMIOS
  45 #       if #cpu(sparc)
  46 #               include <termio.h>
  47 #               define termios termio
  48 #               define setTermSettings(fd,argp) ioctl(fd,TCSETAF,argp)
  49 #               define getTermSettings(fd,argp) ioctl(fd,TCGETA,argp)
  50 #       else
  51 #               include <termios.h>
  52 #               define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
  53 #               define getTermSettings(fd,argp) tcgetattr(fd, argp);
  54 #       endif
  55
  56 FILE *cin;
  57
  58 struct termios initial_settings, new_settings;
  59
  60 void gotsig(int sig)
  61 {
  62         setTermSettings(fileno(cin), &initial_settings);
  63         fprintf(stdout, "\n");
  64         exit(TRUE);
  65 }
  66 #endif /* BB_FEATURE_USE_TERMIOS */
  67
  68
  69 static int terminal_width = 79; /* not 80 in case terminal has linefold bug */
  70 static int terminal_height = 24;
  71
  72
  73 extern int more_main(int argc, char **argv)
  74 {
  75         int c, lines = 0, input = 0;
  76         int please_display_more_prompt = 0;
  77         struct stat st;
  78         FILE *file;
  79
  80 #if defined BB_FEATURE_AUTOWIDTH && defined BB_FEATURE_USE_TERMIOS
  81         struct winsize win = { 0, 0 };
  82 #endif
  83
  84         argc--;
  85         argv++;
  86
  87         if (argc > 0
  88                 && (strcmp(*argv, dash_dash_help) == 0 || strcmp(*argv, "-h") == 0)) {
  89                 usage(more_usage);
  90         }
  91         do {
  92                 if (argc == 0) {
  93                         file = stdin;
  94                 } else
  95                         file = fopen(*argv, "r");
  96
  97                 if (file == NULL) {
  98                         perror(*argv);
  99                         exit(FALSE);
 100                 }
 101                 fstat(fileno(file), &st);
 102
 103 #ifdef BB_FEATURE_USE_TERMIOS
 104                 cin = fopen("/dev/tty", "r");
 105                 if (!cin)
 106                         cin = fopen("/dev/console", "r");
 107                 getTermSettings(fileno(cin), &initial_settings);
 108                 new_settings = initial_settings;
 109                 new_settings.c_cc[VMIN] = 1;
 110                 new_settings.c_cc[VTIME] = 0;
 111                 new_settings.c_lflag &= ~ICANON;
 112                 new_settings.c_lflag &= ~ECHO;
 113                 setTermSettings(fileno(cin), &new_settings);
 114
 115 #       ifdef BB_FEATURE_AUTOWIDTH
 116                 ioctl(fileno(stdout), TIOCGWINSZ, &win);
 117                 if (win.ws_row > 4)
 118                         terminal_height = win.ws_row - 2;
 119                 if (win.ws_col > 0)
 120                         terminal_width = win.ws_col - 1;
 121 #       endif
 122
 123                 (void) signal(SIGINT, gotsig);
 124                 (void) signal(SIGQUIT, gotsig);
 125                 (void) signal(SIGTERM, gotsig);
 126
 127 #endif
 128                 while ((c = getc(file)) != EOF) {
 129                         if (please_display_more_prompt) {
 130                                 int len = 0;
 131
 132                                 please_display_more_prompt = 0;
 133                                 lines = 0;
 134                                 len = fprintf(stdout, "--More-- ");
 135                                 if (file != stdin) {
 136                                         len += fprintf(stdout, "(%d%% of %ld bytes)",
 137                                                                    (int) (100 *
 138                                                                                   ((double) ftell(file) /
 139                                                                                    (double) st.st_size)),
 140                                                                    st.st_size);
 141                                 }
 142                                 len += fprintf(stdout, "%s",
 143 #ifdef BB_FEATURE_USE_TERMIOS
 144                                                            ""
 145 #else
 146                                                            "\n"
 147 #endif
 148                                         );
 149
 150                                 fflush(stdout);
 151
 152                                 /*
 153                                  * We've just displayed the "--More--" prompt, so now we need
 154                                  * to get input from the user.
 155                                  */
 156 #ifdef BB_FEATURE_USE_TERMIOS
 157                                 input = getc(cin);
 158 #else
 159                                 input = getc(stdin);
 160 #endif
 161
 162 #ifdef BB_FEATURE_USE_TERMIOS
 163                                 /* Erase the "More" message */
 164                                 while (--len >= 0)
 165                                         putc('\b', stdout);
 166                                 while (++len <= terminal_width)
 167                                         putc(' ', stdout);
 168                                 while (--len >= 0)
 169                                         putc('\b', stdout);
 170                                 fflush(stdout);
 171 #endif
 172
 173                         }
 174
 175                         /*
 176                          * There are two input streams to worry about here:
 177                          *
 178                          *     c : the character we are reading from the file being "mored"
 179                          * input : a character received from the keyboard
 180                          *
 181                          * If we hit a newline in the _file_ stream, we want to test and
 182                          * see if any characters have been hit in the _input_ stream. This
 183                          * allows the user to quit while in the middle of a file.
 184                          */
 185                         if (c == '\n') {
 186                                 switch (input) {
 187                                 case 'q':
 188                                         goto end;
 189                                 case '\n':
 190                                         /* increment by just one line if we are at
 191                                          * the end of this line*/
 192                                         please_display_more_prompt = 1;
 193                                         break;
 194                                 }
 195                                 if (++lines == terminal_height)
 196                                         please_display_more_prompt = 1;
 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                 }
 204                 fclose(file);
 205                 fflush(stdout);
 206
 207                 argv++;
 208         } while (--argc > 0);
 209   end:
 210 #ifdef BB_FEATURE_USE_TERMIOS
 211         gotsig(0);
 212 #endif
 213         return(TRUE);
 214 }