Commodore 1581 - Page 58

EXAMPLES:
To read a file that may contain a CHR$(0), such as a machine
language program file, you could correct any CHR$(0) bytes with
1100 GET#3,G$:IF G$ = "" THEN G$ = CHR$(0)
If an overlong string has managed to be recorded in a file, it may
be read back safely into the computer with GET#, using a loop such as
this
3300 B$ = "" ,
3310 GET#1 A$
3320 IF A$OCHR$(13) THEN B$ = B$+A$:GOTO 3310
The limit for such a technique is 255 characters. It will ignore CHR$(0),
but that may be an advantage in building a text string. If CHR$ (0) is
required in the file, then add the following line:
3315 If A$ = "" THEN A$ = CHR$(0T
GET# may be useful in recovering damaged files, or files with
unknown contents. The BASIC reserved variable ST (the file STatus
variable) can be used to indicate when all of a properly closed file has
been read.
500 GET#2,S$
510 SU = ST:REM REMEMBER FILE STATUS
520 PRINT S$;
530 IF SU = 0 THEN 500.REM IF THERE'S MORE TO BE READ
540 IF SUO64 THEN PRINT "STATUS ERROR: ST = ";SU
Copying ST into SU is often an unneccessary precaution, but must be
done if any other file-handling statement appears between the one
which read from the file and the one that loops back to read again. For
example, it would be required if line 520 was changed to
520 PRINT#1,S$;
Otherwise, the file status checked in line 530 would be that of the
write file, not the read file.
The following table applies to single errors or a combination of two or
more errors.
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