如何从Shell脚本将字符串传递到Makefile？

Question

I tried in the following way

In shell script :

Var='abc xyz' make one myvar=$Var

But when it goes into makefile it is just showing myvar as abc but it is not taking abc xyz as my input

Answer 1

Var='abc xyz' make one myvar=$Var

First of all, when expanding the Var variable in the line above, you may be expanding an undefined variable (ie: Var ). What the line above is doing is just passing an environment variable called Var with that value to the process which is going to run make .

For the same reason, the following line may not print "Hello World" unless Var was previously defined with that value:

Var='Hello World' echo $Var

The following line will however display "Hello World":

Var='Hello World'; echo $Var

$Var in those examples above is being expanded by the shell. The process running echo receives the Var variable, not the shell.

---

Back to the main problem

But when it goes into makefile it is just showing myvar as abc but it is not taking abc xyz as my input

The line

Var='abc xyz'; make one myvar=$Var

is being expanded by the shell as:

Var='abc xyz'; make one myvar=abc xyz

The space above is used as separator for command-line arguments, so the process running make is actually receiving two arguments instead of one in place of the command-line variable:

1. myvar=abc
2. xyz

Solution

You need to scape the space, so that it won't be interpreted as an argument separator by the shell. You can achieve that by placing double quotes around $Var :

Var='abc xyz'; make one myvar="$Var"

This way, the process running make will receive a single argument for the command-line variable: myvar=abc xyz .

Answer 2

Is there a reason you can't just pass it through the environment? Eg,

.PHONY: all
all: DEBUG

.PHONY: DEBUG
DEBUG:
        @echo $(test)

yields

$ test="this is a test" make DEBUG
this is a test