Customization: .mlrrc
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How to use .mlrrc
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Suppose you always use CSV files. Then instead of always having to type ``--csv`` as in

::

    mlr --csv cut -x -f extra mydata.csv

::

    mlr --csv sort -n id mydata.csv

and so on, you can instead put the following into your ``$HOME/.mlrrc``:

::

    --csv

Then you can just type things like

::

    mlr cut -x -f extra mydata.csv

::

    mlr sort -n id mydata.csv

and the ``--csv`` part will automatically be understood. (If you do want to process, say, a JSON file then ``mlr --json ...`` at the command line will override the default from your ``.mlrrc``.)

What you can put in your .mlrrc
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* You can include any command-line flags, except the "terminal" ones such as ``--help``.

* The formatting rule is you need to put one flag beginning with ``--`` per line: for example, ``--csv`` on one line and ``--nr-progress-mod 1000`` on a separate line.

* Since every line starts with a ``--`` option, you can leave off the initial ``--`` if you want. For example, ``ojson`` is the same as ``--ojson``, and ``nr-progress-mod 1000`` is the same as ``--nr-progress-mod 1000``.

* Comments are from a ``#`` to the end of the line.

* Empty lines are ignored -- including lines which are empty after comments are removed.

Here is an example ``.mlrrc file``:

::

POKI_INCLUDE_ESCAPED(sample_mlrrc)HERE

Where to put your .mlrrc
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* If the environment variable ``MLRRC`` is set:

  * If its value is ``__none__`` then no ``.mlrrc`` files are processed.  (This is nice for things like regression testing.)

  * Otherwise, its value (as a filename) is loaded and processed. If there are syntax errors, they abort ``mlr`` with a usage message (as if you had mistyped something on the command line). If the file can't be loaded at all, though, it is silently skipped.

  * Any ``.mlrrc`` in your home directory or current directory is ignored whenever ``MLRRC`` is set in the environment.

  * Example line in your shell's rc file: ``export MLRRC=/path/to/my/mlrrc``

* Otherwise:

  * If ``$HOME/.mlrrc`` exists, it's processed as above.

  * If ``./.mlrrc`` exists, it's then also processed as above.

  * The idea is you can have all your settings in your ``$HOME/.mlrrc``, then override maybe one or two for your current directory if you like.
