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  * Licensed under GPLv2 or later, see file License in this tarball for details.
  15  */
  16
  17 #include "busybox.h"
  18
  19
  20 #ifdef CONFIG_FEATURE_USE_TERMIOS
  21 static int cin_fileno;
  22 #include <termios.h>
  23 #define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
  24 #define getTermSettings(fd,argp) tcgetattr(fd, argp);
  25
  26 static struct termios initial_settings, new_settings;
  27
  28 static void set_tty_to_initial_mode(void)
  29 {
  30         setTermSettings(cin_fileno, &initial_settings);
  31 }
  32
  33 static void gotsig(int sig)
  34 {
  35         putchar('\n');
  36         exit(EXIT_FAILURE);
  37 }
  38 #endif /* CONFIG_FEATURE_USE_TERMIOS */
  39
  40
  41 int more_main(int argc, char **argv)
  42 {
  43         int c, lines, input = 0;
  44         int please_display_more_prompt = 0;
  45         struct stat st;
  46         FILE *file;
  47         FILE *cin;
  48         int len, page_height;
  49         int terminal_width;
  50         int terminal_height;
  51
  52         argc--;
  53         argv++;
  54
  55
  56         /* not use inputing from terminal if usage: more > outfile */
  57         if(isatty(STDOUT_FILENO)) {
  58                 cin = fopen(CURRENT_TTY, "r");
  59                 if (!cin)
  60                         cin = xfopen(CONSOLE_DEV, "r");
  61                 please_display_more_prompt = 2;
  62 #ifdef CONFIG_FEATURE_USE_TERMIOS
  63                 cin_fileno = fileno(cin);
  64                 getTermSettings(cin_fileno, &initial_settings);
  65                 new_settings = initial_settings;
  66                 new_settings.c_lflag &= ~ICANON;
  67                 new_settings.c_lflag &= ~ECHO;
  68                 new_settings.c_cc[VMIN] = 1;
  69                 new_settings.c_cc[VTIME] = 0;
  70                 setTermSettings(cin_fileno, &new_settings);
  71                 atexit(set_tty_to_initial_mode);
  72                 (void) signal(SIGINT, gotsig);
  73                 (void) signal(SIGQUIT, gotsig);
  74                 (void) signal(SIGTERM, gotsig);
  75 #endif
  76         } else {
  77                 cin = stdin;
  78         }
  79
  80         do {
  81                 if (argc == 0) {
  82                         file = stdin;
  83                 } else
  84                         file = fopen_or_warn(*argv, "r");
  85                 if(file==0)
  86                         goto loop;
  87
  88                 st.st_size = 0;
  89                 fstat(fileno(file), &st);
  90
  91                 please_display_more_prompt &= ~1;
  92
  93                 get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height);
  94                 if (terminal_height > 4)
  95                         terminal_height -= 2;
  96                 if (terminal_width > 0)
  97                         terminal_width -= 1;
  98
  99                 len=0;
 100                 lines = 0;
 101                 page_height = terminal_height;
 102                 while ((c = getc(file)) != EOF) {
 103
 104                         if ((please_display_more_prompt & 3) == 3) {
 105                                 len = printf("--More-- ");
 106                                 if (file != stdin && st.st_size > 0) {
 107 #if _FILE_OFFSET_BITS == 64
 108                                         len += printf("(%d%% of %lld bytes)",
 109                                                    (int) (100 * ((double) ftell(file) /
 110                                                    (double) st.st_size)), (long long)st.st_size);
 111 #else
 112                                         len += printf("(%d%% of %ld bytes)",
 113                                                    (int) (100 * ((double) ftell(file) /
 114                                                    (double) st.st_size)), (long)st.st_size);
 115 #endif
 116                                 }
 117
 118                                 fflush(stdout);
 119
 120                                 /*
 121                                  * We've just displayed the "--More--" prompt, so now we need
 122                                  * to get input from the user.
 123                                  */
 124                                 input = getc(cin);
 125 #ifndef CONFIG_FEATURE_USE_TERMIOS
 126                                 printf("\033[A"); /* up cursor */
 127 #endif
 128                                 /* Erase the "More" message */
 129                                 putc('\r', stdout);
 130                                 while (--len >= 0)
 131                                         putc(' ', stdout);
 132                                 putc('\r', stdout);
 133                                 len=0;
 134                                 lines = 0;
 135                                 page_height = terminal_height;
 136                                 please_display_more_prompt &= ~1;
 137
 138                                 if (input == 'q')
 139                                         goto end;
 140                         }
 141
 142                         /*
 143                          * There are two input streams to worry about here:
 144                          *
 145                          * c     : the character we are reading from the file being "mored"
 146                          * input : a character received from the keyboard
 147                          *
 148                          * If we hit a newline in the _file_ stream, we want to test and
 149                          * see if any characters have been hit in the _input_ stream. This
 150                          * allows the user to quit while in the middle of a file.
 151                          */
 152                         if (c == '\n') {
 153                                 /* increment by just one line if we are at
 154                                  * the end of this line */
 155                                 if (input == '\n')
 156                                         please_display_more_prompt |= 1;
 157                                 /* Adjust the terminal height for any overlap, so that
 158                                  * no lines get lost off the top. */
 159                                 if (len >= terminal_width) {
 160                                         int quot, rem;
 161                                         quot = len / terminal_width;
 162                                         rem  = len - (quot * terminal_width);
 163                                         if (quot) {
 164                                                 if (rem)
 165                                                         page_height-=quot;
 166                                                 else
 167                                                         page_height-=(quot-1);
 168                                         }
 169                                 }
 170                                 if (++lines >= page_height) {
 171                                         please_display_more_prompt |= 1;
 172                                 }
 173                                 len=0;
 174                         }
 175                         /*
 176                          * If we just read a newline from the file being 'mored' and any
 177                          * key other than a return is hit, scroll by one page
 178                          */
 179                         putc(c, stdout);
 180                         len++;
 181                 }
 182                 fclose(file);
 183                 fflush(stdout);
 184 loop:
 185                 argv++;
 186         } while (--argc > 0);
 187   end:
 188         return 0;
 189 }