============================================
:fas:`file-code;fa-fw` Filename parsing
============================================

The :code:`plot_file` input defines the simulation output directory. Alamo
supports time and dimension wildcards, input-variable substitution, and
Slurm environment substitution in this value.

Time and dimension wildcards
----------------------------

The following wildcard strings are available:

.. code-block:: text

   %Y  Four-digit year
   %m  Two-digit month (01-12)
   %d  Two-digit day of the month (01-31)
   %H  Two-digit hour (00-23)
   %M  Two-digit minute (00-59)
   %S  Two-digit second (00-59)
   %f  Microseconds within the current second
   %D  Spatial dimension

For example:

.. code-block:: makefile

   plot_file = output_%Y%m%d_%H%M%S

may resolve to:

.. code-block:: text

   output_20250307_211201

Input variable substitution
---------------------------

Use braces to substitute a variable from the input file:

.. code-block:: makefile

   myinput.value = 3
   plot_file = output_{myinput.value}

This resolves the output directory to:

.. code-block:: text

   output_3

Slurm environment substitution
------------------------------

Any brace-delimited variable whose name begins with :code:`SLURM_` is read
from the process environment. Common substitutions include:

.. code-block:: text

   {SLURM_JOB_ID}
   {SLURM_JOB_NAME}
   {SLURM_JOB_PARTITION}
   {SLURM_CLUSTER_NAME}
   {SLURM_ARRAY_TASK_ID}

For example:

.. code-block:: makefile

   plot_file = output_{SLURM_JOB_ID}

may resolve to:

.. code-block:: text

   output_314159

If the requested variable is unavailable or empty, its name is retained
without braces:

.. code-block:: text

   output_SLURM_JOB_ID