� >Squash
file$ = "Sample"
�load_source_data
(�compress_data
2�save_compressed_data
<�display_stats
F�
P:
Z:
d� �compress_data
nKș "Squash_Compress", %1000, datasize% � workspacesize%, maxoutputsize%
x#compsize% = 20 + maxoutputsize%
�+� comp% compsize%, work% workspacesize%
�:
�4� Now we set up the 20 byte Squash file's header
�$comp%   = "SQSH"
�comp%!4  = datasize%
�comp%!8  = loadaddr%
�comp%!12 = execaddr%
�comp%!16 = 0
�:
�#� And now we compress the data!
�eș "Squash_Compress", 0, work%, data%, datasize%, comp%+20, compsize%-20 � status%,,,, endoutput%
�E� status%<>0 � 0, "One step compression failed, status "+�status%
��

:

� �display_stats

0� "Source file size:            ", datasize%

"5� "Compression workspace size:  ", workspacesize%

,0� "Maximum compressed file size:", compsize%

67� "Actual compressed file size: ", endoutput%-comp%

@�

J�

T:

^� �save_compressed_data

h>ș "OS_File", 10, �file$, 9)+"X", &FCA,, comp%, endoutput%

r�

|:

�� �load_source_data

�� type%

�Gș "OS_File", 5, file$ � objtype%,, loadaddr%, execaddr%, datasize%

�Z� loadaddr,execaddr will typically hold the file's filetype & datestamp (see PRM 2-14)

�8� objtype%<>1 � 0, "File '"+file$+"' does not exist"

�� data% datasize%

�&ș "OS_File", 255, file$, data%, 0

��
�

00000000  0d 00 0a 0d f4 20 3e 53  71 75 61 73 68 0d 00 14  |..... >Squash...|
00000010  14 66 69 6c 65 24 20 3d  20 22 53 61 6d 70 6c 65  |.file$ = "Sample|
00000020  22 0d 00 1e 15 f2 6c 6f  61 64 5f 73 6f 75 72 63  |".....load_sourc|
00000030  65 5f 64 61 74 61 0d 00  28 12 f2 63 6f 6d 70 72  |e_data..(..compr|
00000040  65 73 73 5f 64 61 74 61  0d 00 32 19 f2 73 61 76  |ess_data..2..sav|
00000050  65 5f 63 6f 6d 70 72 65  73 73 65 64 5f 64 61 74  |e_compressed_dat|
00000060  61 0d 00 3c 12 f2 64 69  73 70 6c 61 79 5f 73 74  |a..<..display_st|
00000070  61 74 73 0d 00 46 05 e0  0d 00 50 05 3a 0d 00 5a  |ats..F....P.:..Z|
00000080  05 3a 0d 00 64 14 dd 20  f2 63 6f 6d 70 72 65 73  |.:..d.. .compres|
00000090  73 5f 64 61 74 61 0d 00  6e 4b c8 99 20 22 53 71  |s_data..nK.. "Sq|
000000a0  75 61 73 68 5f 43 6f 6d  70 72 65 73 73 22 2c 20  |uash_Compress", |
000000b0  25 31 30 30 30 2c 20 64  61 74 61 73 69 7a 65 25  |%1000, datasize%|
000000c0  20 b8 20 77 6f 72 6b 73  70 61 63 65 73 69 7a 65  | . workspacesize|
000000d0  25 2c 20 6d 61 78 6f 75  74 70 75 74 73 69 7a 65  |%, maxoutputsize|
000000e0  25 0d 00 78 23 63 6f 6d  70 73 69 7a 65 25 20 3d  |%..x#compsize% =|
000000f0  20 32 30 20 2b 20 6d 61  78 6f 75 74 70 75 74 73  | 20 + maxoutputs|
00000100  69 7a 65 25 0d 00 82 2b  de 20 63 6f 6d 70 25 20  |ize%...+. comp% |
00000110  63 6f 6d 70 73 69 7a 65  25 2c 20 77 6f 72 6b 25  |compsize%, work%|
00000120  20 77 6f 72 6b 73 70 61  63 65 73 69 7a 65 25 0d  | workspacesize%.|
00000130  00 8c 05 3a 0d 00 96 34  f4 20 4e 6f 77 20 77 65  |...:...4. Now we|
00000140  20 73 65 74 20 75 70 20  74 68 65 20 32 30 20 62  | set up the 20 b|
00000150  79 74 65 20 53 71 75 61  73 68 20 66 69 6c 65 27  |yte Squash file'|
00000160  73 20 68 65 61 64 65 72  0d 00 a0 15 24 63 6f 6d  |s header....$com|
00000170  70 25 20 20 20 3d 20 22  53 51 53 48 22 0d 00 aa  |p%   = "SQSH"...|
00000180  18 63 6f 6d 70 25 21 34  20 20 3d 20 64 61 74 61  |.comp%!4  = data|
00000190  73 69 7a 65 25 0d 00 b4  18 63 6f 6d 70 25 21 38  |size%....comp%!8|
000001a0  20 20 3d 20 6c 6f 61 64  61 64 64 72 25 0d 00 be  |  = loadaddr%...|
000001b0  18 63 6f 6d 70 25 21 31  32 20 3d 20 65 78 65 63  |.comp%!12 = exec|
000001c0  61 64 64 72 25 0d 00 c8  10 63 6f 6d 70 25 21 31  |addr%....comp%!1|
000001d0  36 20 3d 20 30 0d 00 d2  05 3a 0d 00 dc 23 f4 20  |6 = 0....:...#. |
000001e0  41 6e 64 20 6e 6f 77 20  77 65 20 63 6f 6d 70 72  |And now we compr|
000001f0  65 73 73 20 74 68 65 20  64 61 74 61 21 0d 00 e6  |ess the data!...|
00000200  65 c8 99 20 22 53 71 75  61 73 68 5f 43 6f 6d 70  |e.. "Squash_Comp|
00000210  72 65 73 73 22 2c 20 30  2c 20 77 6f 72 6b 25 2c  |ress", 0, work%,|
00000220  20 64 61 74 61 25 2c 20  64 61 74 61 73 69 7a 65  | data%, datasize|
00000230  25 2c 20 63 6f 6d 70 25  2b 32 30 2c 20 63 6f 6d  |%, comp%+20, com|
00000240  70 73 69 7a 65 25 2d 32  30 20 b8 20 73 74 61 74  |psize%-20 . stat|
00000250  75 73 25 2c 2c 2c 2c 20  65 6e 64 6f 75 74 70 75  |us%,,,, endoutpu|
00000260  74 25 0d 00 f0 45 e7 20  73 74 61 74 75 73 25 3c  |t%...E. status%<|
00000270  3e 30 20 85 20 30 2c 20  22 4f 6e 65 20 73 74 65  |>0 . 0, "One ste|
00000280  70 20 63 6f 6d 70 72 65  73 73 69 6f 6e 20 66 61  |p compression fa|
00000290  69 6c 65 64 2c 20 73 74  61 74 75 73 20 22 2b c3  |iled, status "+.|
000002a0  73 74 61 74 75 73 25 0d  00 fa 05 e1 0d 01 04 05  |status%.........|
000002b0  3a 0d 01 0e 14 dd 20 f2  64 69 73 70 6c 61 79 5f  |:..... .display_|
000002c0  73 74 61 74 73 0d 01 18  30 f1 20 22 53 6f 75 72  |stats...0. "Sour|
000002d0  63 65 20 66 69 6c 65 20  73 69 7a 65 3a 20 20 20  |ce file size:   |
000002e0  20 20 20 20 20 20 20 20  20 22 2c 20 64 61 74 61  |         ", data|
000002f0  73 69 7a 65 25 0d 01 22  35 f1 20 22 43 6f 6d 70  |size%.."5. "Comp|
00000300  72 65 73 73 69 6f 6e 20  77 6f 72 6b 73 70 61 63  |ression workspac|
00000310  65 20 73 69 7a 65 3a 20  20 22 2c 20 77 6f 72 6b  |e size:  ", work|
00000320  73 70 61 63 65 73 69 7a  65 25 0d 01 2c 30 f1 20  |spacesize%..,0. |
00000330  22 4d 61 78 69 6d 75 6d  20 63 6f 6d 70 72 65 73  |"Maximum compres|
00000340  73 65 64 20 66 69 6c 65  20 73 69 7a 65 3a 22 2c  |sed file size:",|
00000350  20 63 6f 6d 70 73 69 7a  65 25 0d 01 36 37 f1 20  | compsize%..67. |
00000360  22 41 63 74 75 61 6c 20  63 6f 6d 70 72 65 73 73  |"Actual compress|
00000370  65 64 20 66 69 6c 65 20  73 69 7a 65 3a 20 22 2c  |ed file size: ",|
00000380  20 65 6e 64 6f 75 74 70  75 74 25 2d 63 6f 6d 70  | endoutput%-comp|
00000390  25 0d 01 40 05 f1 0d 01  4a 05 e1 0d 01 54 05 3a  |%..@....J....T.:|
000003a0  0d 01 5e 1b dd 20 f2 73  61 76 65 5f 63 6f 6d 70  |..^.. .save_comp|
000003b0  72 65 73 73 65 64 5f 64  61 74 61 0d 01 68 3e c8  |ressed_data..h>.|
000003c0  99 20 22 4f 53 5f 46 69  6c 65 22 2c 20 31 30 2c  |. "OS_File", 10,|
000003d0  20 c0 66 69 6c 65 24 2c  20 39 29 2b 22 58 22 2c  | .file$, 9)+"X",|
000003e0  20 26 46 43 41 2c 2c 20  63 6f 6d 70 25 2c 20 65  | &FCA,, comp%, e|
000003f0  6e 64 6f 75 74 70 75 74  25 0d 01 72 05 e1 0d 01  |ndoutput%..r....|
00000400  7c 05 3a 0d 01 86 17 dd  20 f2 6c 6f 61 64 5f 73  ||.:..... .load_s|
00000410  6f 75 72 63 65 5f 64 61  74 61 0d 01 90 0b ea 20  |ource_data..... |
00000420  74 79 70 65 25 0d 01 9a  47 c8 99 20 22 4f 53 5f  |type%...G.. "OS_|
00000430  46 69 6c 65 22 2c 20 35  2c 20 66 69 6c 65 24 20  |File", 5, file$ |
00000440  b8 20 6f 62 6a 74 79 70  65 25 2c 2c 20 6c 6f 61  |. objtype%,, loa|
00000450  64 61 64 64 72 25 2c 20  65 78 65 63 61 64 64 72  |daddr%, execaddr|
00000460  25 2c 20 64 61 74 61 73  69 7a 65 25 0d 01 a4 5a  |%, datasize%...Z|
00000470  f4 20 6c 6f 61 64 61 64  64 72 2c 65 78 65 63 61  |. loadaddr,execa|
00000480  64 64 72 20 77 69 6c 6c  20 74 79 70 69 63 61 6c  |ddr will typical|
00000490  6c 79 20 68 6f 6c 64 20  74 68 65 20 66 69 6c 65  |ly hold the file|
000004a0  27 73 20 66 69 6c 65 74  79 70 65 20 26 20 64 61  |'s filetype & da|
000004b0  74 65 73 74 61 6d 70 20  28 73 65 65 20 50 52 4d  |testamp (see PRM|
000004c0  20 32 2d 31 34 29 0d 01  ae 38 e7 20 6f 62 6a 74  | 2-14)...8. objt|
000004d0  79 70 65 25 3c 3e 31 20  85 20 30 2c 20 22 46 69  |ype%<>1 . 0, "Fi|
000004e0  6c 65 20 27 22 2b 66 69  6c 65 24 2b 22 27 20 64  |le '"+file$+"' d|
000004f0  6f 65 73 20 6e 6f 74 20  65 78 69 73 74 22 0d 01  |oes not exist"..|
00000500  b8 15 de 20 64 61 74 61  25 20 64 61 74 61 73 69  |... data% datasi|
00000510  7a 65 25 0d 01 c2 26 c8  99 20 22 4f 53 5f 46 69  |ze%...&.. "OS_Fi|
00000520  6c 65 22 2c 20 32 35 35  2c 20 66 69 6c 65 24 2c  |le", 255, file$,|
00000530  20 64 61 74 61 25 2c 20  30 0d 01 cc 05 e1 0d ff  | data%, 0.......|
00000540