Experimental Physics and
Industrial Control System

Eric Norum <[email protected]> · Tue, 13 Mar 2007 17:27:06 -0500

After some more investigation it appears that nothing needs to be
changed. None of the systems we looked at need an explicit call to
tzset() after changes are made to TZ.
I was misled by a bug in the current newlib implementation of these
routines. The bug should affect only RTEMS IOCs. Until this bug is
fixed it is necessary to explicitly specify the daylight savings time
offset from UTC:
epicsEnvSet TZ "CST6CDT5,M3.2.0,M11.1.0"

On Mar 13, 2007, at 11:34 AM, Eric Norum wrote:
I think that WIN32 does provide this routine -- at least my quick
check with google seems to imply this.

The vxWorks case is a little trickier. I suppose that someone out
there actually uses the IOC shell rather than the vxWorks shell.

What's' your feeling on weak references?

How about an epicsTzset() macro in some os-dependent header. This
would do nothing on vxWorks and expand to tzset() on all others.
On Mar 13, 2007, at 11:17 AM, Andrew Johnson wrote:
Eric Norum wrote:

Since we're on the topic of time, I'd like to propose the
following change to the IOC shell. This is in the handler
function for the epicsEnvSet command.

...

 epicsEnvSet (name, value);

+ if (strcmp(name, "TZ") == 0) {

+ extern void tzset(void);

+ tzset();

+ }

}

This will ensure that changes to the TZ environment variable (in
an st.cmd file, for example) actually have an effect.

That change is not portable; according to my reference manual
vxWorks doesn't have a tzset() routine, and I have similar doubts
about WIN32. Maybe the correct solution would be to register an OS-
specific command that can set the IOC's timezone data?
--
The right to be heard does not automatically include
the right to be taken seriously. -- Hubert H. Humphrey

--
Eric Norum <[email protected]>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793

--
Eric Norum <[email protected]>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System