How to pass argument from Makefile to a program? [closed]

问题

I want to pass directory of Makefile to a function.

For example:

Makefile

$(DIR) = makefile directory

program

int main(int argc,char argv[]) char directory = argv[1]

How can I do that?

EDIT Clarificaion. I want my app to work outside of the directory that i compiled it in.

回答1:

Passing a symbol at compile time is done with the -D option (example is C++ but you can transpose to C easily). You can either only define the symbol, or give it a value (which is what you want here).

DIR=$(shell pwd)
mytarget: 
    @echo "DIRECTORY=$(DIR)"
    $(CXX) mysource.cpp -D"DIRECTORY=$(DIR)" -o mysource

Then, in your source file, the symbol DIRECTORY will hold the path. To check this, you need an additional trick (known as "double expansion"):

#define STR1(x)  #x
#define STR(x)  STR1(x)
#include <iostream>
int main()
{
    std::cout << "directory is " << STR(DIRECTORY) << "\n";
}

You can check this similar question, and see here about the D flag.

回答2:

In case the directory you need to pass is static (i.e. always the same) you can use the -D C compiler option:

cc -DDIRECTORY=/home/user/...

In your C source code you can then use DIRECTORY.

来源：https://stackoverflow.com/questions/48261350/how-to-pass-argument-from-makefile-to-a-program

标签

makefile