Makefile what is "SHELL = bash"

Question

I'm newbie with shell script.

I saw some shell script code here https://github.com/weidai11/cryptopp/blob/master/GNUmakefile

I just want to know what does it mean~

SHELL = bash

please let me know where the documentation is.

Answer 1

What you saw isn't a shell script, but a Makefile.

SHELL is the Makefile variable that sets the preferred shell to use. The default on is /bin/sh, so if you need Bash features, you might have to set this variable.

Documentation here.

If it was a shell-script, SHELL would be an environment variable that points to the the user's default shell.