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From: tihor@NYU-ACF4.ARPA (Stephen Tihor)
Newsgroups: mod.computers.vax
Subject: Re: Need Help with VAX/VMS C
Message-ID: <8602210503.AA13577@nyu-acf4.arpa>
Date: Fri, 21-Feb-86 00:03:17 EST
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Posted: Fri Feb 21 00:03:17 1986
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        ... the following occurs:

Access violation, reason mask=01, virtual address=7473B3C2, PC=00016831, PSL=03C
00000

        Being a Unix* hack, I have no idea what this means.  

Being a VMS user I know to look up errors in the manual (try doing `man
bus error` on most unix systems.)  Explains says trying to through a bad 
location.  Ah ha he thinks a parameter error in:#
   ...
   lib$set_symbol("COL*OR", "WRITE SYS$OUTPUT \"\27[2J\27[H\"", tab);
   lib$set_symbol("CL*EAR", "WRITE SYS$OUTPUT \"\27[0;41;33m\27[A\"", tab);
=> lib$delete_symbol("ONE", tab);
   lib$delete_symbol("LOGOUT", tab);
   max=strlen(name)-14;
   ...

Checking the one line subroutine summaries: HELP LIB$ LIB$DELETE_SYMBOL
I see that the second parameter is the address of a longword containing the
symbol table number.  tab might contain that from the code given, but
wait:

        I've run it with 'tab' as an int with value 2, and with 'tab'
        #define'd as 2, and it makes no difference.  When this function
        is called from a basic program it works fine.  Can anyone tell me
        why this is happening, and how I can correct it?

Ah ha, you are passing a (long) the value of tab, the integer 2, which is a 
bad address as we all know instead of a (* long) such as &tab which is 
what the routine wants.