// Number.cmm  CEnvi program to find the first number in a program's output

#define  DEFAULT_INDEX  1

main(ArgCount,ArgStrings)
{
   Index = DEFAULT_INDEX
   if ( ArgCount != 1
     && ( ArgCount != 2  ||  0 == (Index = atoi(ArgStrings[1])) ) )
      Instructions()
   else {
      HowManyFound = 0; // this will keep a list of how many numbers found so far
      while ( (input = gets()) ) {
         // get the next number in this line
         while ( (input = strpbrk(input,"-0123456789")) ) {
            if ( '-' == input[0] && !isdigit(input[1]) ) {
               // this was a negative sign, but no numbers follow
               input++
            } else {
               // convert these digits to a number
               NumberList[HowManyFound] = atol(input)
               if ( ++HowManyFound == Index )
                     return(NUMBER = NumberList[HowManyFound-1])
               // skip past all the digits text
               input += 1 + strspn(input+1,"0123456789")
            }
         }
      }
      if ( Index < 0 ) {
         // if enough numbers have been found, then find this offset from the end
         if ( -Index <= HowManyFound ) {
            return(NUMBER = NumberList[HowManyFound+Index])
         }
      }
   }
   // if did not return earlier, then number was not found
   undefine(NUMBER)
   return(0)
}

Instructions()
{
   printf("\a\n")
   printf("Find#.cmm - Read input for numbers. Set the NUMBER environment variable to the\n")
   printf("            number found and return ERRORLEVEL to number found. 0 if not found.\n")
   printf("\n")
   printf("USAGE: CEnvi Find#.cmm [Index]\n")
   printf("\n")
   printf("Where Index tells which found number to return, where 1 is the first number\n")
   printf("found, 2 is the seconds number, and so on; -1 is the last number found, -2 is\n")
   printf("the second to last number, and so on.  If Index is not supplied then the\n")
   printf("default is 1.  If the number is not found then NUMBER is cleared.\n")
   printf("\n")
   printf("Example: To find how many bytes are used the current directory:\n")
   printf("             dir | cenvi Find#.cmm -2\n")
   printf("\n")
}