lean@sbcs.UUCP (Lean L. Loh) (09/18/87)
Since quite a few people asked for this, here is the BASIC program
for UUDECODE. Use this to uudecode a uuencoded real UUDECODING program
(get one), and use the resulting UUDECODE.ttp subsequently because this
BASIC version is very slow.
----------------------------
10 ' UUDECODE PROGRAM
11 ' /*
12 ' * Uudecode -- decode a uuencoded file back to binary form
13 ' *
14 ' * Slightly modified from a version posted to net.sources once;
15 ' * suitable for compilation on an IBM PC.
16 ' *
17 ' * modified for Lattice C on the ST - 11.05.86 by MSD
18 ' *
19 ' * rewritten for ST BASIC on the Atari ST - September 9, 1986,
20 ' * by Patrick Simon
21 ' *
22 ' */
23 ' Initializations.
24 DIM I(4)
25 FULLW 2 : CLEARW 2 ' Use full output window, clear it.
26 MASK = 63 : SP = ASC(" ")
30 ' Get input filename and open file.
40 INPUT "Enter name of uuencoded file > ", IFILEN$
50 OPEN "I", #1, IFILEN$
60 ' Get output filename, open, and set up pointers.
70 INPUT "Enter name of output file > ", OFILEN$
80 OPEN "R", #2, OFILEN$, 45
90 FIELD #2, 45 AS CBUF$
110 ' Input and ignore first line of input file (original filename).
120 LINE INPUT #1, INLINE$ ' Due to a bug in ST BASIC, LINE INPUT #
130 LINE INPUT #1, INLINE$ ' must be called 2x, just to get first
140 ' line. Even then we lose the 1st character.
150 ' Now set up screen for user.
160 CLEARW 2
170 GOTOXY 1,2 : PRINT "Decoding "; IFILEN$; " to "; OFILEN$
180 GOTOXY 1,4 : PRINT "# lines read in: "
190 GOTOXY 1,5 : PRINT "# bytes output: "
200 ' Initialize some variables for main body of program.
210 NUML = 0 : BYTEOUT = 0
220 LINELOOP: ' Now loop for as long as there are input lines.
230 LINE INPUT #1, INLINE$ ' LINE INPUT should work OK by now!
231 IF INLINE$ = "end" THEN GOTO 500 ' All done
232 NUML = NUML + 1
240 ' For each line, must "decode" each byte.
241 ' First byte contains # bytes to ***output*** from this line.
242 ' Then, after decoding, each set of 4 input bytes contains 6*4 = 24
243 ' bits of information to output, 8 bits per output byte, thus
244 ' 3 output bytes.
250 ' Set up string position pointer for INLINE$
260 SPTR = 1
270 ' Get first byte = # bytes to output; exit if line has zero to output
280 GOSUB DECODE : NN = C : N = NN : IF NN = 0 THEN GOTO 500
285 ' Process one line of input
290 MPTR = 1
300 WHILE N > 0 ' Decode set of 4 input bytes.
310 FOR J = 1 TO 4
320 GOSUB DECODE : I(J) = C
330 NEXT J
340 C1 = ((I(1) * 4) MOD 256) + INT(I(2) / 16)
350 C2 = ((I(2) * 16) MOD 256) + INT(I(3) / 4)
360 C3 = ((I(3) * 64) MOD 256) + I(4)
370 IF N>0 THEN MID$(CBUF$,MPTR,1)=CHR$(C1) : MPTR = MPTR + 1
380 IF N>1 THEN MID$(CBUF$,MPTR,1)=CHR$(C2) : MPTR = MPTR + 1
390 IF N>2 THEN MID$(CBUF$,MPTR,1)=CHR$(C3) : MPTR = MPTR + 1
400 N = N - 3
410 WEND ' If more in this line, go back again.
415 ' Finished processing line.
420 PUT #2, NUML ' Send decoded stuff to output file.
430 BYTEOUT = BYTEOUT + NN ' Show status to user.
440 GOTOXY 20,4 : PRINT NUML
445 GOTOXY 20,5 : PRINT BYTEOUT
450 GOTO LINELOOP ' Get next line ...
500 ' Hopefully, we have now decoded the input file.
510 CLOSE #1 : CLOSE #2
520 END
1000 DECODE: ' Subroutine to decode a single character
1010 IF LEN(MID$(INLINE$,SPTR)) = 0 THEN INLINE$ = INLINE$ + " "
1020 CH$ = MID$(INLINE$, SPTR, 1) : SPTR = SPTR + 1
1030 C = (ASC(CH$) - SP) AND MASK
1040 RETURN
--
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