[comp.os.vms] null character terminates DCL command line

MCGUIRE@GRIN1.BITNET ("The Sysco Kid ", McGuire,Ed) (07/27/88)

I SPRed the problem you describe under VAX/VMS Version 3.6.  Here's the text.
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PROBLEM

A null character embedded in the middle of a command line prematurely
terminates the command input scan done by DCL's parsing routines.

RESPONSE

The behavior that you have described is an integral part of DCL's parsing
algorithm.  As each line is read in, either from a terminal or a command
procedure, a null character is placed at the end of the input string to
indicate where the end-of-line is located.  Thus, a command line with an
embedded null character would cause the premature termination of the parse
scan.  Note that an embedded null haracter will not terminate the input of the
command line.  Thus, command procedure verification would not be affected by an
embedded null character.  We do not expect to modify this behavior in the near
future since it would require a major design change.
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Basically this means that if there's a NUL in your command line or you do
quoted substitution of a symbol whose value is a string containing a NUL, your
command line is truncated.  This is only a restriction upon the parse scan.
Ampersand substitution of a symbol containing a null character will succeed
because it occurs after the parse scan.

Ed