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.

                                           Apr 14, 2024                           CLASSAD_EVAL(1)