What value does $(shell pwd) give?

Question

Going through a MakeFile I find

PROJECT_ROOT = $(shell pwd)

What value does it give?

$SHELL gives the shell and $PWD gives present working directory But what does $(shell pwd) give?

Answer 1

The $(shell) function calls out to the shell to execute a command. The command being executed in this case is pwd , like if you ran pwd at the bash shell prompt.

So, $(shell pwd) will return the current working directory. You may not be guaranteed that the $PWD variable exists in your make environment.