Assign a makefile variable value to a bash command result?

Question

I\'m trying to assign the output of this command ( that is in my makefile ) to the makefile HEADER var like in this following line of code:

HEADER = $(shell          


        

Answer 1

You will need to double-escape the $ character within the shell command:

HEADER = $(shell for file in `find . -name *.h`;do echo $$file; done)

The problem here is that make will try to expand $f as a variable, and since it doesn't find anything, it simply replaces it with "". That leaves your shell command with nothing but echo ile, which it faithfully does.

Adding $$ tells make to place a single $ at that position, which results in the shell command looking exactly the way you want it to.

Answer 2

Why not simply do

HEADER = $(shell find . -name '*.h')

Answer 3

The makefile tutorial suggested to use wildcard to get list of files in a directory. In your case, it means this :

HEADERS=$(wildcard *.h)