Q42665: "Bad Record Length" GET#n,,x$ Variable-Length String from File

Article: Q42665
Product(s): See article
Version(s): 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S890222-61 B_BasicCom | mspl13_basic
Last Modified: 14-DEC-1989

The run-time error "Bad record length" occurs when a QuickBASIC
Version 4.00b or 4.50 program uses a variable-length string as the
third argument in a GET statement to input a string that was PUT in
the file as a fixed-length string. This information also applies to
Microsoft BASIC Compiler Version 6.00b for MS-DOS and MS OS/2 and
Microsoft BASIC PDS Version 7.00 for MS-DOS and MS OS/2.

No error occurs in QuickBASIC Version 4.00 or BASIC compiler Version
6.00 because these earlier versions don't expect a 2-byte string
length when you input a variable-length string as the third argument
of the GET statement. For a related article discussing PUT, query on
the following words in this Knowledge Base:

   BAD RECORD LENGTH and PUT

When reading from a random file that was created using fixed-length
strings, you should GET them using fixed-length strings also.

The "Details" listed under "GET" in the QuickBASIC 4.50 QB Advisor
on-line Help system misleadingly suggest using a variable-length
string in the following manner:

   VarStrings$ = STRING$(10, " ")
   GET #1, , VarString$

This method works in QuickBASIC Version 4.00, but not in Versions
4.00b or 4.50.

To avoid the "Bad record length" error message, use a fixed-length
string in your GET statement or create the file using a
variable-length string in QuickBASIC 4.00b or 4.50, BASIC compiler
6.00b, or BASIC PDS 7.00. (Making the variable-length string 2 bytes
longer than the original string does not correct the problem.)

The following code fragment works without error in QuickBASIC Version
4.00 or BASIC compiler 6.00, but gives a "Bad record length" error in
QuickBASIC 4.00b or 4.50, BASIC compiler 6.00b, or BASIC PDS 7.00:

REM  This fragment places information in a file.
REM  It prompts for 8 strings to be placed in a fixed-length
REM  string "a" and then PUT into file #1

OPEN "afile.dat" FOR RANDOM AS #1 LEN = 80
DIM a AS STRING * 80
FOR i = 1 TO 8
  INPUT a
  PUT #1, , a
NEXT i
CLOSE #1

REM  This fragment reads in the data from the file and echoes to the
REM  screen. The strings are retrieved using the statements listed
REM  under "GET" under the "Details" on-line Help hyperlink.
REM  To fix the problem, make VarString$ a fixed-length string
REM  with DIM VarString as string * 80, to replace the STRING$
REM  statement

OPEN "afile.dat" FOR RANDOM AS #1 LEN = 80
VarStrings$ = STRING$(10, " ")
FOR i = 1 TO 8
  GET #1, , VarString$     'this line will give error message
  PRINT VarString$
NEXT i
CLOSE #1

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