[Info-vax] Notable VMS "feature"

[Tom Adams]

On Thursday, January 7, 2016 at 2:28:33 PM UTC-5, VAXman- wrote:
> In article <aec0b901-1099-48bb-899c-70d9952e1010 at googlegroups.com>, Tom Adams <tadamsmar at gmail.com> writes:
> >I have defined a logical name that I cannot deassign
> >
> >A logical name that is 255 characters long that ends with a colon.
> >
> >Here's a command procedure than will do it.
> >
> >$A = "X"
> >$A = A+A
> >$A = A+A
> >$A = A+A
> >$A = A+A
> >$A = A+A
> >$A = A+A
> >$A = A+A
> >$A = A+A
> >$A = F$EXTRACT(0,254,A)
> >$A = A+":"
> >$WRITE SYS$OUTPUT "''F$LENGTH(A)'"
> >$DEFINE 'A FOOBAR
> >$!Cannot deassign using the name because the colon is stripped
> >$ON ERROR THEN CONTINUE
> >$DEASS 'A
> >$!Cannot deassign by adding a extra colon because the name it too long
> >$B = A+':'
> >$DEASS 'B
> >
> >Is there anyway to get rid of this logical name other than logging out?
> >
> 
> 	PROGRAM MY_TERMINAL
> 	IMPLICIT NONE
> 
> 	INCLUDE '($DSCDEF)'
> 	INCLUDE '($JPIDEF)'
> 	INCLUDE '($STSDEF)'
> 	INCLUDE '(LIB$ROUTINES)'
> 	INCLUDE '(STR$ROUTINES)'
> 
> 	INTEGER*4 STATUS
> 
> 	RECORD	/DSCDEF1/ LOGICAL
> 
> 	LOGICAL.DSC$W_MAXSTRLEN = 0
> 	LOGICAL.DSC$B_DTYPE = DSC$K_DTYPE_T
> 	LOGICAL.DSC$B_CLASS = DSC$K_CLASS_D
> 	LOGICAL.DSC$A_POINTER = 0
> 
> 	STATUS = STR$DUPL_CHAR(LOGICAL,254,%REF('X'))
> 	IF (.NOT.(STATUS.AND.STS$M_SUCCESS)) THEN
> 	  CALL SYS$EXIT(%VAL(STATUS))
> 	ENDIF
> 
> 	STATUS = STR$APPEND(LOGICAL,%DESCR(':'))
> 	IF (.NOT.(STATUS.AND.STS$M_SUCCESS)) THEN
> 	  CALL SYS$EXIT(%VAL(STATUS))
> 	ENDIF
> 
> 	STATUS = LIB$DELETE_LOGICAL(LOGICAL,)
> 	CALL SYS$EXIT(%VAL(STATUS))
> 
> 	END
> -- 
> VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG
> 
> I speak to machines with the voice of humanity.

That works!