CompuServe Messages

Arnie, Here's a rexx shellsort routine from the latest book THE AREXX COOKBOOK by Merrill Callaway. I highly recommend the book. Hope this routine helps. /* shellsort.rexx input the file for sorting */ PARSE UPPER ARG infile' 'outfile IF infile = '' THEN DO SAY 'Input sort filename and path: ' PARSE PULL infile END RC=OPEN('sortfile',infile,'READ') IF ~RC THEN DO SAY 'File not opened. Separate arguments with space no comma.' EXIT END k=1 DO WHILE ~EOF('sortfile') list.k=READLN('sortfile') k=k+1 END listlength = k-2 SAY listlength 'entries to sort…' /* The Shell Sort */ RC=TIME('R') span = 1 DO WHILE (span < listlength); span = span * 2; END DO WHILE (span > 1) span = span % 2 numpairs = listlength – span DO node = 1 TO numpairs nextnode = node + span IF list.node > list.nextnode THEN DO store = list.nextnode list.nextnode = list.node DO bubpos = node-span TO 1 BY -span WHILE (store < list.bubpos) nextnode = bubpos + span list.nextnode = list.bubpos END bubpos bubpos = bubpos + span list.bubpos = store END END node END SAY 'Elapsed time='TIME('E')' seconds.' /* output results */ IF outfile = '' THEN DO SAY 'Specify filename and path for sorted output.' PARSE PULL outfile IF outfile='' THEN DO SAY 'No output written.' EXIT 5 END END CALL OPEN('outfile',outfile,'WRITE') DO i=1 TO listlength CALL WRITELN('outfile',list.i) END i SAY 'Output has been written to 'outfile EXIT 0