Q26605: BC.EXE "Line Too Long" for Source Lines of 256+ Characters

Article: Q26605
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom | mspl13_basic
Last Modified: 20-JUL-1990

The program below, which has a 263-character-long CONST statement in
one line, runs without error when loaded in QB.EXE or QBX.EXE, but
gives a "Line too long" error when compiled with BC.EXE.

A blank line filled with 256 or more space characters (ASCII byte
value 32) also gives a "Line too long" error at compile time with
BC.EXE. This is difficult to see, unless you put the cursor on the
blank line and press the END key to move the cursor to the actual end
of the line. The column status indicator in the lower-right corner of
the QB.EXE or QBX.EXE environment then shows the number of characters
in that line.

The "Line too long" error occurs by design in both cases above because
the BC.EXE compiler restricts line length to 255 characters, which
includes the CR (carriage return), LF (linefeed), and the underscore
(_) line-continuation character.

This information applies to Microsoft QuickBASIC versions 4.00, 4.00b,
and 4.50 for MS-DOS and to Microsoft BASIC Professional Development
System (PDS) version 7.00 for MS-DOS and MS OS/2.

The QB.EXE and QBX.EXE editors initially prevent you from typing a
line past column 255, but if you move the cursor to a different line,
then back, the editors let you add characters past column 255. Despite
this capability, you should not type lines that exceed 255 characters.
You can easily check the number of characters in any line by placing
the cursor on the line in question, pressing the END key, and looking
at the column counter on the lower-right corner of the screen in the
QB.EXE or QBX.EXE environment.

Code Example
------------

BC.EXE compiles this program correctly if you remove one character to
make the CONST line 262 characters long. Normally, the line limit is
255 characters, but CONST statements are parsed differently than other
lines of code, giving you 7 additional characters of leeway in this
case.

' The following CONST line (where you should type all 263 characters
' on one line to demonstrate the "Line too long" error in BC.EXE)
' can be typed past column 255 in QB.EXE or QBX.EXE if you press the
' DOWN ARROW then the UP ARROW back onto the long line, and
' continue typing:
CONST A$ = "12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890"

PRINT A$

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