This document describes changes that will affect users who migrate
from XPA 1.0 to XPA 2.0.
There have been a few changes that affect users who upgrade XPA
from version 1.0 to version 2.0. These changes are detailed below.
- XPA commands no longer have a resolver routine (this is open to
negotiations, but we decided the idea was dumb). For the SAOtng
program, this means that you must explicitly specify the access
cat foo.fits | xpaset SAOtng fits
cat foo.fits | xpaset SAOtng
- By default, xpaset, xpaget, etc. now wait for the server callback to
complete; i.e., the old -W is implied (and the switch is ignored).
This allows support for better error handling. If you want xpaset, etc.
to return before the callback is complete, use -n switch:
echo "file foo.fits" | xpaset -n SAOtng
- The old -w switch in xpaset and xpaget is no longer necessary (and is
ignored), since you can have more than one process communicating with
an xpa access point at one time.
- The new -p switch on xpaset means you need not read from stdout:
xpaset -p SAOtng colormap I8
will send the paramlist to the SAOtng callback without reading from stdin.
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Last updated: September 10, 2003