main.c

   1 /*
   2 description: sends a sequence of keystrokes provided from stdin to the hid
   3 device.
   4 stops typing at: control characters (including newline), chars not in table, EOF
   5 parameters:
   6         device file (e.g. /dev/hidg0)
   7         keyboard layout (1=en_us, 2=de_at, 3=de_at-nodeadkeys)
   8         unicode method: 1=gtk_holddown, 2=gtk_spaceend, 3=windows
   9 */
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include "scancodes.h"
  14
  15 #define TEXT_LEN 256 //max length of piped text
  16 enum params {//argv-indices:
  17         P_EXE, //executable name
  18         P_DEV, //device file
  19         P_LAY, //layout
  20         P_UNI, //unicode method
  21         NUM_P  //number of parameters
  22 };
  23 enum uni_m {//unicode methods:
  24         SKIP, //ignore any keys not on the layout
  25         GTK_HOLD, //hold ctrl and shift while entering hex values
  26         GTK_SPACE, //end hex sequence with spacebar
  27         WINDOWS //use alt+numpad
  28 };
  29 enum errors {
  30         ERR_SUCCESS, //no error
  31         ERR_ARGCOUNT, //wrong number of arguments
  32         ERR_SYMBOL, //symbol not in look up table
  33         ERR_LAYOUT, //parameter P_LAY does not contain a correct keyboard layout
  34         ERR_LAZY //i haven't done this
  35 };
  36
  37 void send_key (FILE* hid_dev, unsigned short key, unsigned short mod);
  38 enum errors send_unicode (FILE* hid_dev, unsigned int unicode, enum uni_m method, enum kbdl layout);
  39
  40 int main (int argc, char** argv) {
  41         if (argc != NUM_P) {
  42                 fprintf (stderr, "Usage: %s <device file> <layout> <unicode>\n", argv[P_EXE]);
  43                 fprintf (stderr, "Takes string to type from stdin\n");
  44                 fprintf (stderr, "<device file>:\ton the Raspberry Pi usually /dev/hidg0\n");
  45                 fprintf (stderr, "<layout>:\n\t%d\t%s\n\t%d\t%s\n\t%d\t%s\n",
  46                         en_US, "en_US",
  47                         de_AT, "de_AT (w/ dead keys)",
  48                         de_ND, "de_AT-nodeadkeys");
  49                 fprintf (stderr, "<unicode>:\n\t%d\t%s\n\t%d\t%s\n\t%d\t%s\n\t%d\t%s\n",
  50                         SKIP, "skip over unicode characters",
  51                         GTK_HOLD, "X11 Holddown: CTRL+SHIFT+[u, hex]",
  52                         GTK_SPACE, "X11 Space: CTRL+SHIFT+u, hex, SPACE",
  53                         WINDOWS, "Windows: Alt+[Numpad]");
  54                 return ERR_ARGCOUNT;
  55         }
  56         FILE* hid_dev = fopen ("/dev/hidg0", "w");
  57         char in_string[TEXT_LEN];
  58         fgets(in_string, TEXT_LEN, stdin);
  59         for (int i = 0; i < strlen (in_string); i++) {
  60                 if (in_string[i] < 32) {
  61                         if (in_string[i] != '\n') fprintf (stderr, "Cannot print control characters!\n(Is there a newline at the end of your string?\n");
  62                         return ERR_SYMBOL;
  63                 }
  64
  65                 char tmp[UTF8_MAX_LENGTH] = {in_string[i], in_string[i+1], in_string[i+2], '\0'};
  66                 //TODO: replace by something less stupid
  67                 if (in_string[i] < 128) { // not multi byte
  68                         tmp[1] = '\0';
  69                 } else { // is multi byte
  70                         if (in_string[i] < 0xe0) {
  71                         i++; //skip next thing
  72                         tmp[2] = 0;
  73                         } else {
  74                         i+=2; //WARN: fails on utf8 > 3 byte
  75                         }
  76                 }
  77
  78                 struct keysym* s = toscan (tmp);
  79                 if (s == NULL) {
  80                         fprintf (stderr, "Key Symbol not found.\n");
  81 fclose (hid_dev);
  82                         return ERR_SYMBOL;
  83                 }
  84                 struct layout* l = tolay (s, atoi (argv[P_LAY]));
  85                 if (l == NULL) {
  86                         fprintf (stderr, "Unrecognised keyboard layout.\n");
  87 fclose (hid_dev);
  88                         return ERR_LAYOUT;
  89                 }
  90                 if (l->key != 0x00) {
  91                         send_key(hid_dev, l->key, l->mod);
  92                         send_key(hid_dev, '\0', '\0'); //release all keys
  93                         if (l->is_dead) {
  94                                 //dead keys need to be pressed twice to show up
  95                                 send_key(hid_dev, l->key, l->mod);
  96                                 send_key(hid_dev, '\0', '\0'); //release all keys
  97                         }
  98                 } else {
  99                         //key does not exist in this layout, use unicode method
 100                         //fprintf (stderr, "Warning: Key '%s'(0x%x) not in this layout!\n", s->sym, s->unicode);
 101                         send_unicode (hid_dev, s->unicode, atoi (argv[P_UNI]), atoi(argv[P_LAY]));
 102                 }
 103         }
 104         fclose (hid_dev);
 105
 106         return ERR_SUCCESS;
 107 }
 108
 109 void send_key (FILE* hid_dev, unsigned short key, unsigned short mod) {
 110         fprintf (hid_dev, "%c%c%c%c%c%c%c%c", mod, '\0', key, '\0', '\0', '\0', '\0', '\0');
 111 }
 112
 113 enum errors send_unicode (FILE* hid_dev, unsigned int unicode, enum uni_m method, enum kbdl layout) {
 114         char buf[10];
 115         struct keysym* s;
 116         struct layout* l;
 117
 118         if (unicode == 0x00) {
 119                 fprintf (stderr, "Symbol not in lookup table!\n");
 120                 return ERR_SYMBOL;
 121         }
 122
 123         switch (method) {
 124         case SKIP:
 125                 break;
 126         case GTK_HOLD:
 127                 sprintf (buf, "%x", unicode);
 128                 s = toscan ("u");
 129                 l = tolay (s, layout);
 130                 send_key (hid_dev, l->key, MOD_LCTRL | MOD_LSHIFT);
 131                 for (int i = 0; i < strlen (buf); i++) {
 132                         s = toscan ((char[2]){buf[i], '\0'});
 133                         l = tolay (s, layout);
 134                         send_key (hid_dev, l->key, MOD_LCTRL | MOD_LSHIFT);
 135                 }
 136                 send_key (hid_dev, '\0', '\0');
 137                 break;
 138         case GTK_SPACE:
 139                 sprintf (buf, "%x ", unicode);
 140                 s = toscan ("u");
 141                 l = tolay (s, layout);
 142                 send_key (hid_dev, l->key, MOD_LCTRL | MOD_LSHIFT);
 143                 for (int i = 0; i < strlen (buf); i++) {
 144                         s = toscan ((char[2]){buf[i], '\0'});
 145                         l = tolay (s, layout);
 146                         send_key (hid_dev, l->key, MOD_NONE);
 147                 }
 148                 send_key (hid_dev, '\0', '\0');
 149                 break;
 150         case WINDOWS:
 151                 fprintf (stderr, "windows method not implemented!\n");
 152                 return ERR_LAZY;
 153         default:
 154                 fprintf (stderr, "unknown unicode method!\n");
 155                 return ERR_LAYOUT; //TODO: better error code
 156         }
 157         return ERR_SUCCESS;
 158 }