How to read file content into a qmake variable and pass it to the compiler?

问题

How to read file content into a variable in qmake project file? For example, I'd like to have the contents of KEY read from a file and pass it to the compiler:

DEFINES += KEY=**some magic and filename here**

回答1:

On all platforms, there's a built-in replace function $$cat:

# set a qmake variable
KEY = "$$cat(/path/to/the/file)"
# propagate the variable to C/C++
DEFINES += "KEY=\"$$KEY\""

The effect of this line is the same as if you added the following line at the beginning of every translation unit:

#define KEY <contents of the file>

Suppose that the file contains a single line:

FOO

Then:

 // source
 qDebug() << KEY;
 // preprocessed source
 qDebug() << "FOO";

来源：https://stackoverflow.com/questions/38962126/qmake-language-read-value-from-text-file-possible