Is there a way to define custom implicit GNU Make rules?

May 10, 2022

I’m often creating png files out of dot (graphviz format) files. The command to do so is the following:

$ dot my_graph.dot -o my_graph.png -Tpng

However, I would like to be able to have a shorter command format like $ make my_graph.dot to automatically generate my png file.

For the moment, I’m using a Makefile in which I’ve defined the following rule, but the recipe is only available in the directory containing the Makefile

%.eps: %.dot
    dot $<  -o $@ -Teps

Is it possible to define custom implicit GNU Make recipes ? Which would allow the above recipe to be available system-wide

If not, what solution do you use to solve those kind of problem ?

Setup:

Fedora Linux with ZSH/Bash

>Solution :

You could define shell functions in your shell’s startup files, e.g.

dotpng()
{
    echo dot ${1%.dot}.dot -o ${1%.dot}.png -Tpng;
}

This function can be called like

dotpng my_graph.dot

dotpng my_graph

_{The code ${1%.dot}.dot strips .dot from the file name if present and appends it (again) to allow both my_graph.dot and my_graph as function argument.}