getline.c

The MEASURE program uses analog and digital inputs to simulate a datalogger. You may watch the va

/*----------------------------------------------------------------------------
 *      Name:    GETLINE.C
 *      Purpose: Line Edited Character Input
 *      Version: V1.10
 *----------------------------------------------------------------------------
 *      This file is part of the uVision/ARM development tools.
 *      This software may only be used under the terms of a valid, current,
 *      end user licence from KEIL for a compatible version of KEIL software
 *      development tools. Nothing else gives you the right to use it.
 *
 *      Copyright (c) 2005-2007 Keil Software.
 *---------------------------------------------------------------------------*/

#include <stdio.h>
#include "measure.h"                     /* global project definition file   */

#define CNTLQ      0x11
#define CNTLS      0x13
#define DEL        0x7F
#define BACKSPACE  0x08
#define CR         0x0D
#define LF         0x0A

/***************/
/* Line Editor */
/***************/
void getline (char *line, int n)  {
  int  cnt = 0;
  char c;

  do  {
    if ((c = getkey ()) == CR)  c = LF;     /* read character                 */
    if (c == BACKSPACE  ||  c == DEL)  {    /* process backspace              */
      if (cnt != 0)  {
        cnt--;                              /* decrement count                */
        line--;                             /* and line pointer               */
        putchar (BACKSPACE);                /* echo backspace                 */
        putchar (' ');
        putchar (BACKSPACE);
      }
    }
    else if (c != CNTLQ && c != CNTLS)  {   /* ignore Control S/Q             */
      putchar (*line = c);                  /* echo and store character       */
      line++;                               /* increment line pointer         */
      cnt++;                                /* and count                      */
    }
  }  while (cnt < n - 1  &&  c != LF);      /* check limit and line feed      */
  *(line - 1) = 0;                          /* mark end of string             */
}