Background
We often want to test the output with different values for a parameter. Here’s
an example: we have a parameter that
pandoc uses to / compile source code files to PDF / M$ Word / etc.
rm output.html; param=0; pandoc input$param.txt -o output.html; \
echo param = $param
In practice, a parameter can be a font, the font size, etc, and there can be
multiple parameters.