I had a case where I had to detect the difference between two versions of Fedora, to tweak the command-line options for inkscape:
- in Fedora 31, the default inkscape is 1.0beta which uses --export-file
- in Fedora < 31, the default inkscape is 0.92 which uses --export-pdf
My Makefile contains the following
# set VERSION_ID from /etc/os-release$(eval $(shell grep VERSION_ID /etc/os-release))# select the inkscape export syntaxifeq ($(VERSION_ID),31)EXPORT = export-fileelseEXPORT = export-pdfendif# rule to convert inkscape SVG (drawing) to PDF%.pdf : %.svg inkscape --export-area-drawing $< --$(EXPORT)=$@This works because /etc/os-release contains a line
VERSION_ID=<value>so the shell command in the Makefile returns the string VERSION_ID=<value>, then the eval command acts on this to set the Makefile variable VERSION_ID.This can obviously be tweaked for other OS's depending how the metadata is stored. Note that in Fedora there is not a default environment variable that gives the OS version, otherwise I would have used that!