*********************
Questions and Answers
*********************

Absent Features
===============

How do I color output?
----------------------

Para leaves coloring output to other tools (e.g., Colout_,
the `Generic Colouriser <grc_>`_, or Supercat_).

However, if a program's output is prefixed with its name, as required
by :manpage:`style(9)` and the GNU coding standards (`chap. 4.4
<https://www.gnu.org/prep/standards/html_node/Errors.html#Errors>`_),
then the output can be colored with :manpage:`tput(1)` and
:manpage:`sed(1)`.

Generate the ANSI escape codes for your
favorite colors with :command:`tput`:

.. code:: bash

    blue="$(tput setaf 4)"
    cyan="$(tput setaf 6)"
    reset="$(tput sgr0)"

.. tip::
    See :manpage:`terminfo(5)` for how numbers map to colors.

Then pipe :command:`para`'s output through a :command:`sed`-script
that applies them:

.. code:: bash

    para 'echo foo: qux' 'echo bar: quux' |
    sed "
        s/\(^foo:\)\(.*\)/$blue\1$reset\2/;
        s/\(^bar:\)\(.*\)/$cyan\1$reset\2/;
    "


Troubleshooting
===============

``-l: getloadavg(3) not available``
-----------------------------------

The load average is queried with :manpage:`getloadavg(3)`. However,
:c:func:`getloadavg` is not supported by the system or not declared in
:file:`stdlib.h`, or Para has been compiled to only use interfaces
standardized by POSIX.1-2008_ (:c:func:`getloadavg` is non-standard).

You can try to recompile para with::

    ./configure CPPFLAGS=
    make


``Environment full`` or ``Too many variables``
----------------------------------------------

By default, Para permits only 255 variables in a job's environment.
You can raise that limit by re-compiling Para with :c:macro:`MAX_NVARS`
set to a higher value. For example,

.. code:: bash

    ./configure -DMAX_NVARS=2048
    make

configures Para to permit up to 2047 environment variables
(one slot is needed for a terminator).


:samp:`para.c:{line}: {error}`
------------------------------

Error messages that mention :file:`para.c` indicate bugs.
Please be so kind and :doc:`report them <feedback>`.


:samp:`wordsplit: Invalid argument` or :samp:`-k: Invalid argument`
-------------------------------------------------------------------

Arguments are invalid if they cannot be split into words. This happens
when they contain unbalanced quotes or end with an escape (:samp:`\\`).