Important Changes for Release 1.9

  http://hea-www.harvard.edu/RD/xpa/index.html

Because this is the first release of xpa 2.0, we are most anxious to hear about any problems that you might have. Please send mail to saord@cfa.harvard.edu. Here are a list of changes to xpa that will be of interest to users of SAOtng:

• Multiple instances of SAOtng having the same name now can be run at the same time on the same machine. If you use the same name for more than one SAOtng, XPA commands can be sent to multiple image displays simultaneously.

• The new XPA system uses its own access control mechanism, rather than X11 access controls (xhost, xauth, etc.). If you are running SAOtng on one machine and using xpaset and xpaget on another, please read the XPA documentation on access control in saord/xpa-2.0/doc/acl.html or http://hea-www.harvard.edu/RD/xpa/acl.html.

• 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 have explicitly specify the fits access point, i.e.,:

    cat foo.fits | xpaset SAOtng fits
  

  instead of:

    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.