[Info-vax] Notable VMS "feature"

[VAXman- at SendSpamHere.ORG]

In article <4779702f-8074-4cdd-b809-1cf36c20a162 at googlegroups.com>, Tom Adams <tadamsmar at gmail.com> writes:
>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!

BTW, your procedure uncovered a minor issue within my DCL debugger.  Thanks.
-- 
VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG

I speak to machines with the voice of humanity.