/* CGI utility function definitions - C version */



static char
hex2char(char *x)
/****************************************************************/
/* converts the two digit hex number pointed to by x to the     */
/* corresponding ASCII character.                               */
/****************************************************************/
{
  char c;

  /* note : (x & 0xdf) makes x upper case */
  c = (x[0] >= 'A' ? ((x[0] & 0xdf) - 'A') + 10: (x[0] - '0'));
  c *=16;
  c +=(x[1] >= 'A' ? ((x[1] & 0xdf) - 'A') + 10: (x[1] - '0'));

  return c;
}



void
splitword(char *output, char *input, char separator)
/*************************************************************************/
/* extracts first word terminated by the separator character from input, */
/* places it in output and left shifts rest of input                     */
/*************************************************************************/
{
  int i,j;

  for (i=0; input[i] && (input[i] != separator); i++)
    output[i] = input[i];

  output[i] = '\0';
  if (input[i])
    i++;
  else
  {
    input[0] = '\0';
    return;
  }

  /* left shift the rest */
  for (j=0; input[i]; )
    input[j++] = input[i++];
  input[j]  = '\0';
}



void
unescape_url(char *url)
/****************************************************************/
/* decodes the CGI encoded string from the web browser          */
/****************************************************************/
{
  int i, j;

  for (i=0, j=0; url[j]; ++i,++j)
  {
    /* replace all hex values with corresponding characters */
    if ((url[i] = url[j]) == '%')
    {
      url[i] = hex2char(&url[j+1]);
      j += 2;
    }
    else if (url[i] == '+')
      url[i] = ' ';
  }

  url[i] = '\0';   /* terminate url after the processing */
}