reactos/lib/crt/conio/cgets.c

   1 /*
   2  * COPYRIGHT:        See COPYING in the top level directory
   3  * PROJECT:          ReactOS kernel
   4  * FILE:             msvcrt/conio/cgets.c
   5  * PURPOSE:          C Runtime
   6  * PROGRAMMER:       Eric Kohl (Imported from DJGPP)
   7  */
   8
   9 #include <conio.h>
  10 #include <stdlib.h>
  11
  12 /*
  13  * @implemented
  14  */
  15 char *_cgets(char *string)
  16 {
  17   unsigned len = 0;
  18   unsigned int maxlen_wanted;
  19   char *sp;
  20   int c;
  21   /*
  22    * Be smart and check for NULL pointer.
  23    * Don't know wether TURBOC does this.
  24    */
  25   if (!string)
  26     return(NULL);
  27   maxlen_wanted = (unsigned int)((unsigned char)string[0]);
  28   sp = &(string[2]);
  29   /*
  30    * Should the string be shorter maxlen_wanted including or excluding
  31    * the trailing '\0' ? We don't take any risk.
  32    */
  33   while(len < maxlen_wanted-1)
  34   {
  35     c=_getch();
  36     /*
  37      * shold we check for backspace here?
  38      * TURBOC does (just checked) but doesn't in cscanf (thats harder
  39      * or even impossible). We do the same.
  40      */
  41     if (c == '\b')
  42     {
  43       if (len > 0)
  44       {
  45         _cputs("\b \b");        /* go back, clear char on screen with space
  46                                    and go back again */
  47         len--;
  48         sp[len] = '\0';         /* clear the character in the string */
  49       }
  50     }
  51     else if (c == '\r')
  52     {
  53       sp[len] = '\0';
  54       break;
  55     }
  56     else if (c == 0)
  57     {
  58       /* special character ends input */
  59       sp[len] = '\0';
  60       _ungetch(c);              /* keep the char for later processing */
  61       break;
  62     }
  63     else
  64     {
  65       sp[len] = _putch(c);
  66       len++;
  67     }
  68   }
  69   sp[maxlen_wanted-1] = '\0';
  70   string[1] = (char)((unsigned char)len);
  71   return(sp);
  72 }
  73
  74