.. include:: <isotech.txt>
dchmod
======

SYNOPSIS
--------

**dchmod [OPTION] PATH ...**

DESCRIPTION
-----------

Parallel MPI application to recursively change permissions and/or group
from a top level directory.

dchmod provides functionality similar to :manpage:`chmod(1)`, :manpage:`chown(1)`, and :manpage:`chgrp(1)`.
Like :manpage:`chmod(1)`, the tool supports the use of octal or symbolic mode to
change the permissions.

OPTIONS
-------

.. option:: -i, --input FILE

   Read source list from FILE. FILE must be generated by another tool
   from the mpiFileUtils suite.

.. option:: -u, --owner USER

   Change owner to specified USER name.

.. option:: -g, --group GROUP

   Change group to specified GROUP name.

.. option:: -m, --mode MODE

   The mode to apply to each item. MODE may be octal or symbolic syntax
   similar to :manpage:`chmod(1)`. In symbolic notation, "ugoa" are supported
   as are "rwxX". As with chmod, if no leading letter "ugoa" is provided,
   mode bits are combined with umask to determine the actual mode.

.. option:: --exclude REGEX

   Do not modify items whose full path matches REGEX, processed by
   :manpage:`regexec(3)`.

.. option:: --match REGEX

   Only modify items whose full path matches REGEX, processed by
   :manpage:`regexec(3)`.

.. option:: --name

   Change --exclude and --match to apply to item name rather than its
   full path.

.. option:: -v, --verbose

   Run in verbose mode. Prints a list of statistics including the
   number of files walked, the number of levels there are in the
   directory tree, and the number of files the command operated on, and
   the files/sec rate for each of those.

.. option:: -h, --help

   Print the command usage, and the list of options available.

EXAMPLES
--------

1. Use octal mode to change permissions:

``mpirun -np 128 dchmod --mode 755 /directory``

2. Set group and mode in a single command using symbolic mode:

``mpirun -np 128 dchmod --group mygroup --mode u+r,g+rw /directory``

3. Set owner and group, leaving permissions the same:

``mpirun -np 128 dchmod --owner user1 --group mygroup /directory``

4. Change permissions to u+rw on all items EXCEPT those whose name match
   regex:

``mpirun -np 128 dchmod --name --exclude ‘afilename’ --mode u+rw /directory``

Note: You can use --match to change file permissions on all of the
files/directories that match the regex.

SEE ALSO
--------

The mpiFileUtils source code and all documentation may be downloaded
from <https://github.com/hpc/mpifileutils>