getline.c

ARM实例程序

/*----------------------------------------------------------------------------
 *      R T L   F l a s h   F i l e   S y s t e m   E x a m p l e
 *----------------------------------------------------------------------------
 *      Name:    GETLINE.C
 *      Purpose: Line Edited Character Input
 *      Rev.:    V3.20
 *----------------------------------------------------------------------------
 *      This code is part of the RealView Run-Time Library.
 *      Copyright (c) 2004-2008 KEIL - An ARM Company. All rights reserved.
 *---------------------------------------------------------------------------*/

#include <RTL.h>
#include <stdio.h>

#include "SD_File.h"

/*----------------------------------------------------------------------------
 *      Line Editor
 *---------------------------------------------------------------------------*/
BOOL getline (char *lp, U32 n) {
   U32 cnt = 0;
   char c;

   do {
      c = getkey ();
      switch (c) {
         case CNTLQ:                       /* ignore Control S/Q             */
         case CNTLS:
            break;;
         case BACKSPACE:
         case DEL:
            if (cnt == 0) {
               break;
            }
            cnt--;                         /* decrement count                */
            lp--;                          /* and line pointer               */
            putchar (0x08);                /* echo backspace                 */
            putchar (' ');
            putchar (0x08);
            fflush (stdout);
            break;
         case ESC:
            *lp = 0;                       /* ESC - stop editing line        */
            return (__FALSE);
         case CR:                          /* CR - done, stop editing line   */
            *lp = c;
            lp++;                          /* increment line pointer         */
            cnt++;                         /* and count                      */
            c = LF;
         default:
            putchar (*lp = c);             /* echo and store character       */
            fflush (stdout);
            lp++;                          /* increment line pointer         */
            cnt++;                         /* and count                      */
            break;
      }
   } while (cnt < n - 2  &&  c != LF);     /* check limit and CR             */
   *lp = 0;                                /* mark end of string             */
   return (__TRUE);
}

/*----------------------------------------------------------------------------
 * end of file
 *---------------------------------------------------------------------------*/