<-p -4> is not a valid option
usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
  file1                    File name of the first HDF5 file
  file2                    File name of the second HDF5 file
  [obj1]                   Name of an HDF5 object, in absolute path
  [obj2]                   Name of an HDF5 object, in absolute path

  OPTIONS
   -h, --help              Print a usage message and exit.
   -V, --version           Print version number and exit.
   -r, --report            Report mode. Print differences.
   -v --verbose            Verbose mode. Print differences information and list
                           of objects.
   -vN --verbose=N         Verbose mode with level. Print differences and list
                           of objects.
                           Level of detail depends on value of N:
                            0 : Identical to '-v' or '--verbose'.
                            1 : All level 0 information plus one-line attribute
                                status summary.
                            2 : All level 1 information plus extended attribute
                                status report.
   -q, --quiet             Quiet mode. Do not produce output.
   --follow-symlinks       Follow symbolic links (soft links and external links)
                           and compare the links' target objects.
                           If symbolic link(s) with the same name exist in the
                           files being compared, then determine whether the 
                           target of each link is an existing object (dataset,
                           group, or named datatype) or the link is a dangling
                           link (a soft or external link pointing to a target
                           object that does not yet exist).
                           - If both symbolic links are dangling links, they
                             are treated as being the same; by default, h5diff
                             returns an exit code of 0. If, however, 
                             --no-dangling-links is used with --follow-symlinks,
                             this situation is treated as an error and h5diff 
                             returns an exit code of 2.
                           - If only one of the two links is a dangling link,
                             they are treated as being different and h5diff 
                             returns an exit code of 1. If, however, 
                             --no-dangling-links is used with --follow-symlinks,
                             this situation is treated as an error and h5diff 
                             returns an exit code of 2.
                           - If both symbolic links point to existing objects,
                             h5diff compares the two objects.
                           If any symbolic link specified in the call to h5diff
                           does not exist, h5diff treats it as an error and
                           returns an exit code of 2.
   --no-dangling-links     Must be used with --follow-symlinks option;
                           otherwise, h5diff shows error message and returns
                           an exit code of 2.
                           Check for any symbolic links (soft links or external
                           links) that do not resolve to an existing object
                           (dataset, group, or named datatype).  If any
                           dangling link is found, this situation is treated as
                           an error and h5diff returns an exit code of 2.
   -c, --compare           List objects that are not comparable
   -N, --nan               Avoid NaNs detection
   -n C, --count=C         Print differences up to C number, C is a positive
                           integer.
   -d D, --delta=D         Print difference if (|a-b| > D), D is a positive
                           number.
   -p R, --relative=R      Print difference if (|(a-b)/b| > R), R is a positive
                           number.
   --use-system-epsilon    Print difference if (|a-b| > EPSILON), EPSILON is
                           a system epsilon value.
                           If the system epsilon is not defined, the below
                           one of the following predefined values will be used:
                             FLT_EPSILON = 1.19209E-07 for floating-point type
                             DBL_EPSILON = 2.22045E-16 for double percision type
   --exclude-path "path"   Exclude the specified path to an object when
                           comparing files or groups. If a group is excluded,
                           all member objects will also be excluded.
                           The specified path is excluded wherever it occurs.
                           This flexibility enables the same option to exclude
                           either objects that exist only in one file or
                           common objects that are known to differ.

                           When comparing files, "path" is the absolute path to
                           the excluded object; when comparing groups, "path" is
                           similar to the relative path from the group to the
                           excluded object. This "path" can be taken from the
                           first section of the output of the --verbose option.
                           For example, if you are comparing the group /groupA
                           in two files and you want to exclude
                           /groupA/groupB/groupC in both files, the exclude
                           option would read as follows:
                             --exclude-path "/groupB/groupC"

                           If there are multiple paths to an object, only the
                           specified path(s) will be excluded; the comparison
                           will include any path not explicitly excluded.
                           This option can be used repeatedly to exclude
                           multiple paths.

 Modes of output:
  Default mode: print the number of differences found and where they occured
  -r Report mode: print the above plus the differences
  -v Verbose mode: print the above plus a list of objects and warnings
  -q Quiet mode: do not print output

 File comparison:
  If no objects [obj1[ obj2]] are specified, the h5diff comparison proceeds as
  a comparison of the two files' root groups.  That is, h5diff first compares
  the names of root group members, generates a report of root group objects
  that appear in only one file or in both files, and recursively compares
  common objects.

 Object comparison:
  1) Groups 
      First compares the names of member objects (relative path, from the
      specified group) and generates a report of objects that appear in only
      one group or in both groups. Common objects are then compared recursively.
  2) Datasets 
      Array rank and dimensions, datatypes, and data values are compared.
  3) Datatypes 
      The comparison is based on the return value of H5Tequal.
  4) Symbolic links 
      The paths to the target objects are compared.
      (The option --follow-symlinks overrides the default behavior when
       symbolic links are compared.).

 Exit code:
  0 if no differences, 1 if differences found, 2 if error

 Examples of use:
 1) h5diff file1 file2 /g1/dset1 /g1/dset2
    Compares object '/g1/dset1' in file1 with '/g1/dset2' in file2

 2) h5diff file1 file2 /g1/dset1
    Compares object '/g1/dset1' in both files

 3) h5diff file1 file2
    Compares all objects in both files

 Notes:
  file1 and file2 can be the same file.
  Use h5diff file1 file1 /g1/dset1 /g1/dset2 to compare
  '/g1/dset1' and '/g1/dset2' in the same file

EXIT CODE: 1