tldr/pages/common/m4.md

m4

Macro processor. More information: https://www.gnu.org/software/m4/manual/m4.html#Invoking-m4.

• Process macros in a file:

m4 {{path/to/file}}

• Define a macro before processing files:

m4 {{[-D|--define]}} {{macro_name}}={{macro_value}} {{path/to/file}}