Usermode/Libraries/libreadline.so_src/main.c

   1 /*
   2  * Acess2 Library Suite
   3  * - Readline
   4  *
   5  * Text mode entry with history
   6  */
   7 #include <readline.h>
   8 #include <stdlib.h>
   9
  10 // === GLOBALS ===
  11
  12 // === CODE ===
  13 char *Readline(tReadline *Info)
  14 {
  15         char    *ret;
  16          int    len, pos, space = 1023-8-8;     // optimised for the heap manager
  17         char    ch;
  18          int    scrollbackPos = Info->NumHistory;
  19
  20         // Preset Variables
  21         ret = malloc( space+1 );
  22         if(!ret)        return NULL;
  23         len = 0;        pos = 0;
  24
  25         // Read In Command Line
  26         do {
  27                 read(_stdin, 1, &ch);   // Read Character from stdin (read is a blocking call)
  28
  29                 if(ch == '\n')  break;
  30
  31                 switch(ch)
  32                 {
  33                 // Control characters
  34                 case '\x1B':
  35                         read(_stdin, 1, &ch);   // Read control character
  36                         switch(ch)
  37                         {
  38                         //case 'D':     if(pos) pos--;  break;
  39                         //case 'C':     if(pos<len)     pos++;  break;
  40                         case '[':
  41                                 read(_stdin, 1, &ch);   // Read control character
  42                                 switch(ch)
  43                                 {
  44                                 case 'A':       // Up
  45                                         {
  46                                                  int    oldLen = len;
  47                                                 if( scrollbackPos <= 0 )        break;
  48
  49                                                 free(ret);
  50                                                 ret = strdup( Info->History[--scrollbackPos] );
  51
  52                                                 len = strlen(ret);
  53                                                 while(pos--)    write(_stdout, 3, "\x1B[D");
  54                                                 write(_stdout, len, ret);       pos = len;
  55                                                 while(pos++ < oldLen)   write(_stdout, 1, " ");
  56                                         }
  57                                         break;
  58                                 case 'B':       // Down
  59                                         {
  60                                                  int    oldLen = len;
  61                                                 if( scrollbackPos >= Info->NumHistory ) break;
  62
  63                                                 free(ret);
  64                                                 ret = strdup( Info->History[scrollbackPos++] );
  65
  66                                                 len = strlen(ret);
  67                                                 while(pos--)    write(_stdout, 3, "\x1B[D");
  68                                                 write(_stdout, len, ret);       pos = len;
  69                                                 while(pos++ < oldLen)   write(_stdout, 1, " ");
  70                                         }
  71                                         break;
  72                                 case 'D':       // Left
  73                                         if(pos == 0)    break;
  74                                         pos --;
  75                                         write(_stdout, 3, "\x1B[D");
  76                                         break;
  77                                 case 'C':       // Right
  78                                         if(pos == len)  break;
  79                                         pos++;
  80                                         write(_stdout, 3, "\x1B[C");
  81                                         break;
  82                                 }
  83                         }
  84                         break;
  85
  86                 // Backspace
  87                 case '\b':
  88                         if(len <= 0)            break;  // Protect against underflows
  89                         write(_stdout, 1, &ch);
  90                         if(pos == len) {        // Simple case of end of string
  91                                 len --;
  92                                 pos--;
  93                         }
  94                         else {
  95                                 char    buf[7] = "\x1B[000D";
  96                                 buf[2] += ((len-pos+1)/100) % 10;
  97                                 buf[3] += ((len-pos+1)/10) % 10;
  98                                 buf[4] += (len-pos+1) % 10;
  99                                 write(_stdout, len-pos, &ret[pos]);     // Move Text
 100                                 ch = ' ';       write(_stdout, 1, &ch); ch = '\b';      // Clear deleted character
 101                                 write(_stdout, 7, buf); // Update Cursor
 102                                 // Alter Buffer
 103                                 memmove(&ret[pos-1], &ret[pos], len-pos);
 104                                 pos --;
 105                                 len --;
 106                         }
 107                         break;
 108
 109                 // Tab
 110                 case '\t':
 111                         //TODO: Implement Tab-Completion
 112                         //Currently just ignore tabs
 113                         break;
 114
 115                 default:
 116                         // Expand Buffer
 117                         if(len+1 > space) {
 118                                 space += 256;
 119                                 ret = realloc(ret, space+1);
 120                                 if(!ret)        return NULL;
 121                         }
 122
 123                         // Editing inside the buffer
 124                         if(pos != len) {
 125                                 char    buf[7] = "\x1B[000D";
 126                                 buf[2] += ((len-pos)/100) % 10;
 127                                 buf[3] += ((len-pos)/10) % 10;
 128                                 buf[4] += (len-pos) % 10;
 129                                 write(_stdout, 1, &ch); // Print new character
 130                                 write(_stdout, len-pos, &ret[pos]);     // Move Text
 131                                 write(_stdout, 7, buf); // Update Cursor
 132                                 memmove( &ret[pos+1], &ret[pos], len-pos );
 133                         }
 134                         else {
 135                                 write(_stdout, 1, &ch);
 136                         }
 137                         ret[pos++] = ch;
 138                         len ++;
 139                         break;
 140                 }
 141         } while(ch != '\n');
 142
 143         // Cap String
 144         ret[len] = '\0';
 145         printf("\n");
 146
 147         // Return length
 148         //if(Length)    *Length = len;
 149
 150         // Add to history
 151         if( Info->UseHistory )
 152         {
 153                 if( strcmp( Info->History[ Info->NumHistory-1 ], ret) != 0 )
 154                 {
 155                         void    *tmp;
 156                         Info->NumHistory ++;
 157                         tmp = realloc( Info->History, Info->NumHistory * sizeof(char*) );
 158                         if(tmp != NULL)
 159                         {
 160                                 Info->History = tmp;
 161                                 Info->History[ Info->NumHistory-1 ] = strdup(ret);
 162                         }
 163                 }
 164         }
 165
 166         return ret;
 167 }