INNAME

DIM

120

OUTNAME

DIM

120

BLOCK

DIM

65531

NEXTREC

INTEGER

4

LENGTH

INTEGER

2

MODE

DIM

1

SEQ

FORM

"-1"

INSIZE

FORM

10

OUTSIZE

FORM

10

.

IN

FILE

OUT

FILE

.

COMPREC

RECORD

SRCSIZE

INTEGER

2

CMPSIZE

INTEGER

2

DATA

DIM

65531

RECORDEND

*.........................................................................

.

.Get the file names

.

KEYIN

*HD,*R,"Enter the input file name: ",INNAME

TYPE

INNAME

STOP

IF EOS

.

KEYIN

*HD,*R,"Enter the output file name: ",OUTNAME

TYPE

OUTNAME

STOP

IF EOS

*

.Get the direction

.

KEYIN

*HD,*R,"(C)ompress or (U)ncompress? ",MODE

CMATCH

"U",MODE

GOTO

UNCOMPRESS IF EQUAL

CMATCH

"C",MODE

STOP

IF NOT EQUAL

*............................................................................

.

.Compress a file

.

OPEN

IN,INNAME,EXCLUSIVE

PREP

OUT,OUTNAME,EXCLUSIVE

.

LOOP

READ

IN,SEQ;*ABSON,BLOCK;

// read some data

TYPE

BLOCK

// if there was something read,

WHILE

NOT EOS

MOVELPTR

BLOCK,COMPREC.SRCSIZE

// note the original size

COMPRESS

BLOCK,COMPREC.DATA

// compress the data

MOVELPTR

COMPREC.DATA,COMPREC.CMPSIZE

// note the compressed size

WRITE

OUT,SEQ;*ABSON,*LL,COMPREC;

// write the data

REPEAT

// continue

.

GOTO

END

*.............................................................................

.

.Uncompress a File

.

UNCOMPRESS

OPEN

IN,INNAME,EXCLUSIVE

PREP

OUT,OUTNAME,EXCLUSIVE

.

LOOP

REPOSIT

IN,NEXTREC

// position to the next input record

READ

IN,SEQ;*ABSON,COMPREC;

// read a compressed record

TYPE

COMPREC.DATA

// did we find one ?

WHILE

NOT EOS

// stop if nothing read

ADD

(COMPREC.CMPSIZE + 4),NEXTREC

// compute the next compressed record start

SETLPTR

COMPREC.DATA,COMPREC.CMPSIZE

// set the logical length of the block

DECOMPRESS

COMPREC.DATA,BLOCK

// decompress it

MOVELPTR

BLOCK,LENGTH

// get the decompressed length

IF

(LENGTH != COMPREC.SRCSIZE)

// does it match the original size ?

KEYIN

*HD,*R,"Uncompressed data size incorrect.",INNAME

STOP

// die

ENDIF

// otherwise,

WRITE

OUT,SEQ;*ABSON,*LL,BLOCK;

// output the data

REPEAT

// continue

*.................................................................................

.

.Show the results

.

END

CLOSE

IN

CLOSE

OUT

.

FINDFILE

INNAME,FILESIZE=INSIZE

FINDFILE

OUTNAME,FILESIZE=OUTSIZE

.

KEYIN

*HD,*R,"Input file size: ",*DV,INSIZE:

 " Output file size: ",*DV,OUTSIZE:

 " ",INNAME

.

STOP