contrib/less/ttyin.c

   1 /*
   2  * Copyright (C) 1984-2022  Mark Nudelman
   3  *
   4  * You may distribute under the terms of either the GNU General Public
   5  * License or the Less License, as specified in the README file.
   6  *
   7  * For more information, see the README file.
   8  */
   9
  10
  11 /*
  12  * Routines dealing with getting input from the keyboard (i.e. from the user).
  13  */
  14
  15 #include "less.h"
  16 #if OS2
  17 #include "cmd.h"
  18 #include "pckeys.h"
  19 #endif
  20 #if MSDOS_COMPILER==WIN32C
  21 #define WIN32_LEAN_AND_MEAN
  22 #ifndef _WIN32_WINNT
  23 #define _WIN32_WINNT 0x400
  24 #endif
  25 #include <windows.h>
  26 public DWORD console_mode;
  27 public HANDLE tty;
  28 #else
  29 public int tty;
  30 #endif
  31 #if LESSTEST
  32 public char *ttyin_name = NULL;
  33 public int rstat_file = -1;
  34 #endif /*LESSTEST*/
  35 extern int sigs;
  36 extern int utf_mode;
  37 extern int wheel_lines;
  38
  39 #if !MSDOS_COMPILER
  40         static int
  41 open_tty_device(dev)
  42         constant char* dev;
  43 {
  44 #if OS2
  45         /* The __open() system call translates "/dev/tty" to "con". */
  46         return __open(dev, OPEN_READ);
  47 #else
  48         return open(dev, OPEN_READ);
  49 #endif
  50 }
  51
  52 /*
  53  * Open the tty device.
  54  * Try ttyname(), then try /dev/tty, then use file descriptor 2.
  55  * In Unix, file descriptor 2 is usually attached to the screen,
  56  * but also usually lets you read from the keyboard.
  57  */
  58         public int
  59 open_tty(VOID_PARAM)
  60 {
  61         int fd = -1;
  62 #if LESSTEST
  63         if (ttyin_name != NULL)
  64                 fd = open_tty_device(ttyin_name);
  65 #endif /*LESSTEST*/
  66 #if HAVE_TTYNAME
  67         if (fd < 0)
  68         {
  69                 constant char *dev = ttyname(2);
  70                 if (dev != NULL)
  71                         fd = open_tty_device(dev);
  72         }
  73 #endif
  74         if (fd < 0)
  75                 fd = open_tty_device("/dev/tty");
  76         if (fd < 0)
  77                 fd = 2;
  78         return fd;
  79 }
  80 #endif /* MSDOS_COMPILER */
  81
  82 /*
  83  * Open keyboard for input.
  84  */
  85         public void
  86 open_getchr(VOID_PARAM)
  87 {
  88 #if MSDOS_COMPILER==WIN32C
  89         /* Need this to let child processes inherit our console handle */
  90         SECURITY_ATTRIBUTES sa;
  91         memset(&sa, 0, sizeof(SECURITY_ATTRIBUTES));
  92         sa.nLength = sizeof(SECURITY_ATTRIBUTES);
  93         sa.bInheritHandle = TRUE;
  94         tty = CreateFile("CONIN$", GENERIC_READ | GENERIC_WRITE,
  95                         FILE_SHARE_READ, &sa,
  96                         OPEN_EXISTING, 0L, NULL);
  97         GetConsoleMode(tty, &console_mode);
  98         /* Make sure we get Ctrl+C events. */
  99         SetConsoleMode(tty, ENABLE_PROCESSED_INPUT | ENABLE_MOUSE_INPUT);
 100 #else
 101 #if MSDOS_COMPILER
 102         extern int fd0;
 103         /*
 104          * Open a new handle to CON: in binary mode
 105          * for unbuffered keyboard read.
 106          */
 107          fd0 = dup(0);
 108          close(0);
 109          tty = open("CON", OPEN_READ);
 110 #if MSDOS_COMPILER==DJGPPC
 111         /*
 112          * Setting stdin to binary causes Ctrl-C to not
 113          * raise SIGINT.  We must undo that side-effect.
 114          */
 115         (void) __djgpp_set_ctrl_c(1);
 116 #endif
 117 #else
 118         tty = open_tty();
 119 #endif
 120 #endif
 121 }
 122
 123 /*
 124  * Close the keyboard.
 125  */
 126         public void
 127 close_getchr(VOID_PARAM)
 128 {
 129 #if MSDOS_COMPILER==WIN32C
 130         SetConsoleMode(tty, console_mode);
 131         CloseHandle(tty);
 132 #endif
 133 }
 134
 135 #if MSDOS_COMPILER==WIN32C
 136 /*
 137  * Close the pipe, restoring the keyboard (CMD resets it, losing the mouse).
 138  */
 139         int
 140 pclose(f)
 141         FILE *f;
 142 {
 143         int result;
 144
 145         result = _pclose(f);
 146         SetConsoleMode(tty, ENABLE_PROCESSED_INPUT | ENABLE_MOUSE_INPUT);
 147         return result;
 148 }
 149 #endif
 150
 151 /*
 152  * Get the number of lines to scroll when mouse wheel is moved.
 153  */
 154         public int
 155 default_wheel_lines(VOID_PARAM)
 156 {
 157         int lines = 1;
 158 #if MSDOS_COMPILER==WIN32C
 159         if (SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &lines, 0))
 160         {
 161                 if (lines == WHEEL_PAGESCROLL)
 162                         lines = 3;
 163         }
 164 #endif
 165         return lines;
 166 }
 167
 168 #if LESSTEST
 169         public void
 170 rstat(st)
 171         char st;
 172 {
 173         if (rstat_file < 0)
 174                 return;
 175         lseek(rstat_file, SEEK_SET, 0);
 176         write(rstat_file, &st, 1);
 177 }
 178 #endif /*LESSTEST*/
 179
 180 /*
 181  * Get a character from the keyboard.
 182  */
 183         public int
 184 getchr(VOID_PARAM)
 185 {
 186         char c;
 187         int result;
 188
 189         do
 190         {
 191                 flush();
 192 #if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
 193                 /*
 194                  * In raw read, we don't see ^C so look here for it.
 195                  */
 196 #if MSDOS_COMPILER==WIN32C
 197                 if (ABORT_SIGS())
 198                         return (READ_INTR);
 199                 c = WIN32getch();
 200 #else
 201                 c = getch();
 202 #endif
 203                 result = 1;
 204                 if (c == '\003')
 205                         return (READ_INTR);
 206 #else
 207 #if LESSTEST
 208                 rstat('R');
 209 #endif /*LESSTEST*/
 210                 {
 211                         unsigned char uc;
 212                         result = iread(tty, &uc, sizeof(char));
 213                         c = (char) uc;
 214                 }
 215 #if LESSTEST
 216                 rstat('B');
 217 #endif /*LESSTEST*/
 218                 if (result == READ_INTR)
 219                         return (READ_INTR);
 220                 if (result < 0)
 221                 {
 222                         /*
 223                          * Don't call error() here,
 224                          * because error calls getchr!
 225                          */
 226                         quit(QUIT_ERROR);
 227                 }
 228 #endif
 229 #if 0 /* allow entering arbitrary hex chars for testing */
 230                 /* ctrl-A followed by two hex chars makes a byte */
 231         {
 232                 static int hex_in = 0;
 233                 static int hex_value = 0;
 234                 if (c == CONTROL('A'))
 235                 {
 236                         hex_in = 2;
 237                         result = 0;
 238                         continue;
 239                 }
 240                 if (hex_in > 0)
 241                 {
 242                         int v;
 243                         if (c >= '0' && c <= '9')
 244                                 v = c - '0';
 245                         else if (c >= 'a' && c <= 'f')
 246                                 v = c - 'a' + 10;
 247                         else if (c >= 'A' && c <= 'F')
 248                                 v = c - 'A' + 10;
 249                         else
 250                                 v = 0;
 251                         hex_value = (hex_value << 4) | v;
 252                         if (--hex_in > 0)
 253                         {
 254                                 result = 0;
 255                                 continue;
 256                         }
 257                         c = hex_value;
 258                 }
 259         }
 260 #endif
 261                 /*
 262                  * Various parts of the program cannot handle
 263                  * an input character of '\0'.
 264                  * If a '\0' was actually typed, convert it to '\340' here.
 265                  */
 266                 if (c == '\0')
 267                         c = '\340';
 268         } while (result != 1);
 269
 270         return (c & 0xFF);
 271 }