NAME

       hwloc-diff - Compute differences between two XML topologies

SYNOPSIS

       hwloc-diff [options] <input1.xml> <input2.xml>

       hwloc-diff [options] <input1.xml> <input2.xml> <output.xml>

OPTIONS

       --refname <name>
                 Use  <name>  as  the  identifier  for  the  reference topology in the output XML
                 difference.  It is meant to tell which topology should be used when applying the
                 resulting  difference.   hwloc-patch may use that name to automatically load the
                 relevant reference topology XML.  By default, <input1.xml> is used  without  its
                 full path.

       --version Report version and exit.

DESCRIPTION

       hwloc-diff  computes  the difference between two XML topologies and stores the result into
       <output.xml> if any, or dumps it to stdout otherwise.

       The output difference may later be applied to another topology with hwloc-patch.

       hwloc-compress-dir may be used for  computing  the  diffs  between  all  XML  files  in  a
       directory.

       NOTE:  If  some  application-specific  userdata were been exported to the input XMLs, they
       will be ignored and discarded from the output because hwloc has no way to  understand  and
       compare them.

       NOTE:  It  is  highly  recommended that you read the hwloc(7) overview page before reading
       this man page.  Most of the concepts described in hwloc(7) directly apply  to  the  hwloc-
       diff utility.

EXAMPLES

       hwloc-diff's operation is best described through several examples.

       Compute the difference between two XML topologies and output it to stdout:

           $ hwloc-diff fourmi023.xml fourmi024.xml
           Found 11 differences, exporting to stdout
           <?xml version="1.0" encoding="UTF-8"?>
           ...

       Output the difference to file diff.xml instead:

           $ hwloc-diff fourmi023.xml fourmi024.xml diff.xml
           Found 11 differences, exporting to diff.xml

       When the difference is too complex to be represented:

           $ hwloc-diff fourmi023.xml avakas-frontend1.xml
           Found 1 differences, including 1 too complex ones.
           Cannot export differences to stdout

       Directly compute the difference between two topologies and apply it to another one:

           $ hwloc-diff fourmi023.xml fourmi024.xml | hwloc-patch fourmi025.xml -

RETURN VALUE

       Upon successful execution, hwloc-diff outputs the difference.  The return value is 0.

       If the difference is too complex to be represented, an error is returned and the output is
       not generated.

       hwloc-diff also returns nonzero if any kind of error occurs, such as (but not limited  to)
       failure to parse the command line.

SEE ALSO

       hwloc(7), lstopo(1), hwloc-patch(1), hwloc-compress-dir(1)