Question

I have a problem where I want to create a variable that looks like this,

INCDIRS = -I dir0 -I dir1 -Idir2 -I dir3 ... -I dirN

where dir1, … , dirN are the names of all the subdirectories some base directory, base_dir.

How would I go about building up this variable? Originally, I thought I could do the following,

INCDIRS = $(shell for x in `find base_dir -type -d -print`; do echo -I $x; done;)

but this just results in

INCDIRS = -I -I -I -I ... -I

If anyone could explain how to do this, or explain why my original command got the output that it did, I would greatly appreciate it. Thanks!

Answer 1

You have two errors in your INCDIRS assignment. One is in the find command. It should be find -type d -print (or just find -type d; the -print is superfluous here). The other error the use of $x. You need to escape the $ with another $:

INCDIRS = $(shell for x in `find base_dir -type d -print`; do echo -I $$x; done;)