NAME

       classad_eval - HTCondor Manual

       Evaluate  the  given ClassAd expression(s) in the context of the given ClassAd attributes, and prints the
       result in ClassAd format.

SYNOPSIS

       classad_eval -help

       classad_eval [-[ad]-file <file-name>] [-target-file <file-name>] <ad | assignment | expression | -quiet>+

DESCRIPTION

       classad_eval is designed to help you understand and debug ClassAd expressions.  You can supply a  ClassAd
       on  the  command-line, or via a file, as context for evaluating the expression.  You may also construct a
       ClassAd one argument at a time, with assignments.

       By default, classad_eval will print the ClassAd context used to evaluate the expression  before  printing
       the  result  of  the  first  expression, and for every expression with a new ClassAd thereafter.  You may
       suppress this behavior with the -quiet flag, which replaces an ad, assignment, or expression, and  quiets
       every expression after it on the command line.

       Attributes  specified  on  the  command line, including those specified as part of a complete ad, replace
       attributes in the context ad, which starts empty.  You can't remove attributes from the context  ad,  but
       you can set them to undefined.

       Options, flags, and arguments may be freely intermixed, and take effect in order.

       Note  that  classad_eval  uses the new ClassAd syntax: ClassAds specified in a file must be surrounded by
       square brackets and attribute-value pairs must be separated by semicolons.  For compability with condor_q
       -long:new  and  condor_status -long:new, classad_eval will use only the first ClassAd if passed a ClassAd
       list of them.

EXAMPLES

       Almost every ad, assignment, or expression will require  you  to  single  quote  them.   There  are  some
       exceptions; for instance, the following two commands are equivalent:

          $ classad_eval 'a = 2' 'a * 2'
          $ classad_eval a=2 a*2

       You can specify attributes for the context ad in three ways:

          $ classad_eval '[ a = 2; b = 2 ]' 'a + b'
          $ classad_eval 'a = 2; b = 2' 'a + b'
          $ classad_eval 'a = 2' 'b = 2' 'a + b'

       You need not supply an empty ad for expressions that don't reference attributes:

          $ classad_eval 'strcat("foo", "bar")'

       If you want to evaluate an expression in the context of the job ad, first store the job ad in a file:

          $ condor_q -l:new 1227.2 > job.ad
          $ classad_eval -quiet -file job.ad 'JobUniverse'

       You can extract a machine ad in a similar way:

          $ condor_status -l:new slot1@exec-17 > machine.ad
          $ classad_eval -quiet -file machine.ad 'Rank'

       You may evaluate an expression in order to check a match by using the -target-file option:

          $ condor_q -l:new 1227.2 > job.ad
          $ condor_status -l:new exec-17 > machine.ad
          $ classad_eval -quiet -my-file job.ad -target-ad machine.ad 'MY.requirements' 'TARGET.requirements'

       Assignments (including whole ClassAds) are all merged into the context ad:

          $ classad_eval 'x = y' 'x' 'y = 7' 'x' '[ x = 6; z = "foo"; ]' 'x'
          [ x = y ]
          undefined
          [ y = 7; x = y ]
          7
          [ z = "foo"; x = 6; y = 7 ]
          6

       You can suppress printing the context ad partway through:

          $ classad_eval 'x = y' 'x' -quiet 'y = 7' 'x' '[ x = 6; z = "foo"; ]' 'x'
          [ x = y ]
          undefined
          7
          6

EXIT STATUS

       Returns 0 on success.

AUTHOR

       Center for High Throughput Computing, University of Wisconsin-Madison

AUTHOR

       HTCondor Team

COPYRIGHT

       1990-2024,  Center  for High Throughput Computing, Computer Sciences Department, University of Wisconsin-
       Madison, Madison, WI, US. Licensed under the Apache License, Version 2.0.

                                                  Sep 02, 2024                                   CLASSAD_EVAL(1)