I have a makefile where I want to read file name from input and then make other names based on it`s name. I have tried the following code
mlext = .ml
testext = test.ml
nativeext = test.native
test:
@read -p "Enter file name: " file; \
echo $$file$(mlext); \
echo $$file$(testext); \
echo $$file$(nativeext)
for example:
If i type: foo
then I want to get foo.ml, footest.ml, footest.native
however, I can only get foo.ml. For the rest two i only get .ml and .native
How can i fix this?
First, let us see what is the exact recipe given to the shell by removing the @ in your Makefile:
read -p "Enter file name: " file; \
echo $file.ml; \
echo $filetest.ml; \
echo $filetest.native;
The issue is thus that the content of $(testext) gets appended to $$file, creating the shell variable $filetest, which (very probably) does not exist, resulting in an empty string in the end. This does not occur with $(mlext), as the initial dot cannot be part of a variable name.
To overcome this, use $${file} instead of $$file in your Makefile rule.
Collected from the Internet
Please contact [email protected] to delete if infringement.
Comments