tinysh.c

一个简易的Linux下的shell源代码

          putchar('\n');
          return 0;
        }
      else if(ret==UNMATCH)
        {
          puts("\nno match: ");
          puts(str);
          putchar('\n');
          return 0;
        }
      else /* NULLMATCH */
        {
          if(cur_cmd_ctx)
            display_child_help(cur_cmd_ctx->child);
          else
            display_child_help(root_cmd);
          return 0;
        }
    }
}

/* try to complete current command line
 */
static int complete_command_line(tinysh_cmd_t *cmd, uchar *_str)
{
  uchar *str=_str;

  while(1)
    {
      int ret;
      int common_len=BUFFER_SIZE;
      int _str_len;
      int i;
      uchar *__str=str;

      tinysh_cmd_t *_cmd=cmd;
      ret=parse_command(&cmd,&str);
      for(_str_len=0;__str[_str_len]&&__str[_str_len]!=' ';_str_len++);
      if(ret==MATCH && *str)
        {
          cmd=cmd->child;
        }
      else if(ret==AMBIG || ret==MATCH || ret==NULLMATCH)
        {
          tinysh_cmd_t *cm;
          tinysh_cmd_t *matched_cmd=0;
          int nb_match=0;
              
          for(cm=cmd;cm;cm=cm->next)
            {
              int r=strstart(cm->name,__str);
              if(r==FULLMATCH)
                {
                  for(i=_str_len;cmd->name[i];i++)
                    tinysh_char_in(cmd->name[i]);
                  if(*(str-1)!=' ')
                    tinysh_char_in(' ');
                  if(!cmd->child)
                    {
                      if(cmd->usage)
                        {
                          puts(cmd->usage);
                          putchar('\n');
                          return 1;
                        }
                      else
                        return 0;
                    }
                  else
                    {
                      cmd=cmd->child;
                      break;
                    }
                }
              else if(r==PARTMATCH)
                {
                  nb_match++;
                  if(!matched_cmd)
                    {
                      matched_cmd=cm;
                      common_len=strlen(cm->name);
                    }
                  else
                    {
                      for(i=_str_len;cm->name[i] && i<common_len &&
                            cm->name[i]==matched_cmd->name[i];i++);
                      if(i<common_len)
                        common_len=i;
                    }
                }
            }
          if(cm)
            continue;
          if(matched_cmd)
            {
              if(_str_len==common_len)
                {
                  putchar('\n');
                  for(cm=cmd;cm;cm=cm->next)
                    {
                      int r=strstart(cm->name,__str);
                      if(r==FULLMATCH || r==PARTMATCH)
                        {
                          puts(cm->name);
                          putchar('\n');
                        }
                    }
                  return 1;
                }
              else
                {
                  for(i=_str_len;i<common_len;i++)
                    tinysh_char_in(matched_cmd->name[i]);
                  if(nb_match==1)
                    tinysh_char_in(' ');
                }
            }
          return 0;
        }
      else /* UNMATCH */
        { 
          return 0;
        }
    }
}

/* start a new line 
 */
static void start_of_line()
{
  /* display start of new line */
  puts(prompt);
  if(cur_context)
    {
      puts(context_buffer);
      puts("> ");
    }
  cur_index=0;
}

/* character input 
 */
static void _tinysh_char_in(uchar c)
{
  uchar *line=input_buffers[cur_buf_index];

  if(c=='\n' || c=='\r') /* validate command */
    {
      tinysh_cmd_t *cmd;
      int context=0;
      
/* first, echo the newline */
      if(echo)
        putchar(c);

      while(*line && *line==' ') line++;
      if(*line) /* not empty line */
        {
          cmd=cur_cmd_ctx?cur_cmd_ctx->child:root_cmd;
          exec_command_line(cmd,line);
          cur_buf_index=(cur_buf_index+1)%HISTORY_DEPTH;
          cur_index=0;
          input_buffers[cur_buf_index][0]=0;
        }
      start_of_line();
    }
  else if(c==TOPCHAR) /* return to top level */
    {
      if(echo)
        putchar(c);

      cur_context=0;
      cur_cmd_ctx=0;
    }
  else if(c==8 || c==127) /* backspace */
    {
      if(cur_index>0)
        {
          puts("\b \b");
          cur_index--;
          line[cur_index]=0;
        }
    }
  else if(c==16) /* CTRL-P: back in history */
    {
      int prevline=(cur_buf_index+HISTORY_DEPTH-1)%HISTORY_DEPTH;

      if(input_buffers[prevline][0])
        {
          line=input_buffers[prevline];
          /* fill the rest of the line with spaces */
          while(cur_index-->strlen(line))
            puts("\b \b");
          putchar('\r');
          start_of_line();
          puts(line);
          cur_index=strlen(line);
          cur_buf_index=prevline;
        }
    }
  else if(c==14) /* CTRL-N: next in history */
    {
      int nextline=(cur_buf_index+1)%HISTORY_DEPTH;

      if(input_buffers[nextline][0])
        {
          line=input_buffers[nextline];
          /* fill the rest of the line with spaces */
          while(cur_index-->strlen(line))
            puts("\b \b");
          putchar('\r');
          start_of_line();
          puts(line);
          cur_index=strlen(line);
          cur_buf_index=nextline;
        }
    }
  else if(c=='?') /* display help */
    {
      tinysh_cmd_t *cmd;
      cmd=cur_cmd_ctx?cur_cmd_ctx->child:root_cmd;
      help_command_line(cmd,line);
      start_of_line();
      puts(line);
      cur_index=strlen(line);
    }
  else if(c==9 || c=='!') /* TAB: autocompletion */
    {
      tinysh_cmd_t *cmd;
      cmd=cur_cmd_ctx?cur_cmd_ctx->child:root_cmd;
      if(complete_command_line(cmd,line))
        {
          start_of_line();
          puts(line);
        }
      cur_index=strlen(line);
    }      
  else /* any input character */
    {
      if(cur_index<BUFFER_SIZE)
        {
          if(echo)
            putchar(c);
          line[cur_index++]=c;
          line[cur_index]=0;
        }
    }
}

/* new character input */
void tinysh_char_in(uchar c)
{
  /*
   * filter characters here
   */
  _tinysh_char_in(c);
}

/* add a new command */
void tinysh_add_command(tinysh_cmd_t *cmd)
{
  tinysh_cmd_t *cm;

  if(cmd->parent)
    {
      cm=cmd->parent->child;
      if(!cm)
        {
          cmd->parent->child=cmd;
        }
      else
        {
          while(cm->next) cm=cm->next;
          cm->next=cmd;
        }
    }
  else if(!root_cmd)
    {
      root_cmd=cmd;
    }
  else
    {
      cm=root_cmd;
      while(cm->next) cm=cm->next;
      cm->next=cmd;      
    }
}

/* modify shell prompt
 */
void tinysh_set_prompt(char *str)
{
  int i;
  for(i=0;str[i] && i<PROMPT_SIZE;i++)
    prompt[i]=str[i];
  prompt[i]=0;
  /* force prompt display by generating empty command */
  tinysh_char_in('\r');
}

/* return current command argument
 */
void *tinysh_get_arg()
{
  return tinysh_arg;
}

/* string to decimal/hexadecimal conversion
 */
unsigned long tinysh_atoxi(char *s)
{
  int ishex=0;
  unsigned long res=0;

  if(*s==0) return 0;

  if(*s=='0' && *(s+1)=='x')
    {
      ishex=1;
      s+=2;
    }

  while(*s)
    {
      if(ishex)
	res*=16;
      else
	res*=10;

      if(*s>='0' && *s<='9')
	res+=*s-'0';
      else if(ishex && *s>='a' && *s<='f')
	res+=*s+10-'a';
      else if(ishex && *s>='A' && *s<='F')
	res+=*s+10-'A';
      else
	break;
      
      s++;
    }

  return res;
}