handlers.c

这是有名的＜＜嵌入式系统TCP/IP应用层协议＞＞,M.Tim Jones 著

/*
 *  Embedded CLI Command Handler Functions
 *
 *  ./software/ch9/emcli/emclid/handlers.c
 *
 *  [e-mail]
 *
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

extern int getArgCount( void );
extern char *getArg( int );

#define MAX_STACK	20
static int stack[MAX_STACK];
static int stackPtr = 0;

int doHelp ( int fd )
{
  int i;
  char *helptext[]={
         "\nEmbedded CLI Help\n\n",
         "\thelp            - This help\n",
         "\tverbose         - Toggle verbose mode (more output)\n",
         "\thexof <dec num> - Display the hex value of the dec arg\n",
         "\tdecof <hex num> - Display the dec value of the hex arg\n",
         "\tuptime          - Display the number of seconds of uptime\n",
         "\twho             - Display peer IP address and port\n",
         "\tlast            - Display time of last connection\n",
         "\tpush <num>      - Push <num> on the stack\n",
         "\tpop             - Pop and display the top of the stack\n",
         "\tadd             - Pop top two elements, push the sum\n",
         "\tsub             - Pop top two elements, push the difference\n",
         "\tmul             - Pop top two elements, push the product\n",
         "\tdiv             - Pop top two elements, push the quotient\n"

        };

  for (i = 0 ; i < (sizeof(helptext)/sizeof(char *)) ; i++) {
    write(fd, helptext[i], strlen(helptext[i]));
  }

  return 0;
}


int convdec ( int fd )
{
  char response[81];

  if (getArgCount() < 1) return -1;

  sprintf(response, "0x%x\n", atoi(getArg(0)));
  write(fd, response, strlen(response));

  return 0;
}


int convhex ( int fd )
{
  char response[81];
  int  value;

  if (getArgCount() < 1) return -1;

  sscanf(getArg(0), "%x", &value);
  sprintf(response, "%d\n", value);
  write(fd, response, strlen(response));

  return 0;
}


int getpeer ( int fd )
{
  char response[81];
  struct sockaddr_in sockinfo;
  int  len;

  if (getpeername( fd, (struct sockaddr *)&sockinfo, &len ) < 0) {
    return -1;
  } else {

    sprintf(response, "Peer address %s port %d\n", 
             inet_ntoa(sockinfo.sin_addr), ntohs(sockinfo.sin_port) );
    write(fd, response, strlen(response));

  }
  
  return 0;
}


int push ( int fd )
{
  if ((getArgCount() != 1) || (stackPtr == MAX_STACK)) return -1;

  stack[stackPtr++] = atoi(getArg(0));

  return 0;
}


int pop ( int fd )
{
  char response[81];

  if (stackPtr == 0) return -1;

  sprintf(response, "%d\n", stack[--stackPtr]);
  write(fd, response, strlen(response));

  return 0;
}


int mathop ( int fd, char opcode )
{
  int  value1, value2, result;

  if (stackPtr < 2) return -1;

  value2 = stack[--stackPtr];
  value1 = stack[--stackPtr];

  if (value2 == 0) return -1;

  switch(opcode) {
    case 'a':
      result = value1 + value2;
      break;
    case 's':
      result = value1 - value2;
      break;
    case 'm':
      result = value1 * value2;
      break;
    case 'd':
      result = value1 / value2;
      break;
  }

  stack[stackPtr++] = result;

  return 0;
}

/*
 *  Copyright (c) 2002 Charles River Media.  All rights reserved.
 * 
 *  Redistribution and use in source and binary forms, with or 
 *  without modification, is hereby granted without fee provided 
 *  that the following conditions are met:
 * 
 *    1.  Redistributions of source code must retain the above 
 *        copyright notice, this list of conditions and the 
 *        following disclaimer.
 *    2.  Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the 
 *        following disclaimer in the documentation and/or other 
 *        materials provided with the distribution.
 *    3.  Neither the name of Charles River Media nor the names of 
 *        its contributors may be used to endorse or promote products 
 *        derived from this software without specific prior 
 *        written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY CHARLES RIVER MEDIA AND CONTRIBUTERS 
 * 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL CHARLES
 * RIVER MEDIA OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARAY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 */