REXX Tips & Tricks, Version 2.80


Inf-HTML [About][Toc][Index] 0.9b (c) 1995 Peter Childs


Unpack packed data




Unpack routine from Steve Pitts (see EMail Addresses) 
Captured from a message in a public CompuServe Forum 


 
/* ------------------------------------------------------------------ */
/* function: unpack routine for packed data (from mainframes)         */
/*                                                                    */
/* call:     unpack packed_str {,num_dec}                             */
/*                                                                    */
/* where:    packed_str = the packed data                             */
/*           num_dec = number of decimals (def.: 0)                   */
/*                                                                    */
/*                                                                    */
/* returns:  the unpacked number or "" in case of an error            */
/*                                                                    */
Unpack: PROCEDURE
  parse arg packed_str, num_dec

  if num_dec = "" then
    num_dec=0

                        /* Convert packed data to hex and split into  */
                        /* number and sign portions                   */
  hex_str=c2x( packed_str )
  dec_str=left( hex_str, length( hex_str )-1 )
  packed_sign=right( hex_str, 1 )

                        /* Check that sign and numeric portions have  */
                        /* valid values                               */
  if verify( packed_sign, "ABCDEF" ) > 0 then
    return ""

  if verify( dec_str, "0123456789" ) > 0 then
    return ""

                        /* Are there enough digits for the decimal    */
                        /* point??                                    */
  if num_dec > length( dec_str ) then
    return ""

                        /* If sign portion indicates a negative       */
                        /* number then oblige                         */
  if pos( packed_sign, "BD" ) > 0 then
    dec_str=0-dec_str

                        /* If there is a decimal point then add it at */
                        /* the appropriate place                      */
  if num_dec > 0 then
    dec_str=insert( ".", dec_str, length( dec_str )-num_dec )

RETURN dec_str

  

Inf-HTML End Run - Successful