CODEWITHSUNDEEP
cmake
Lars Bilke
Lars Bilke

Reputation: 5229

How to get the working directory of the cmake process?

How to get the working directory from which cmake was called?

I know that I can run execute_process() at the beginning of my CMake code but maybe there is some better way like a built-in variable to the working directory of the CMake process.

What I want to achieve is to convert a relative path given in a CMake variable (given with -D...) to an absolute path in CMake.

Upvotes: 3

Views: 5528

Answers (1)

Alex Reinking
Alex Reinking

Reputation: 19916

What I want to achieve is to convert a relative path given in a CMake variable (given with -D...) to an absolute path in CMake.

Then simply create a cache variable of type PATH (for directories) or FILEPATH in your CMakeLists.txt. CMake will convert untyped command line arguments to absolute paths automatically.

$ cat CMakeLists.txt
cmake_minimum_required(VERSION 3.22)
project(test NONE)

set(input_file "" CACHE FILEPATH "some input file")
message(STATUS "${input_file}")

$ cmake -S . -B build -Dinput_file=foo.txt
-- /path/to/foo.txt
-- Configuring done
-- Generating done
-- Build files have been written to: /path/to/build

See the documentation:

It is possible for the cache entry to exist prior to the call but have no type set if it was created on the cmake(1) command line by a user through the -D<var>=<value> option without specifying a type. In this case the set command will add the type. Furthermore, if the <type> is PATH or FILEPATH and the <value> provided on the command line is a relative path, then the set command will treat the path as relative to the current working directory and convert it to an absolute path.

Here: https://cmake.org/cmake/help/latest/command/set.html?highlight=current%20working%20directory

Relatedly, when running in script mode (rather than project mode), several of the usual variables are set to the current working directory:

When run in -P script mode, CMake sets the variables CMAKE_BINARY_DIR, CMAKE_SOURCE_DIR, CMAKE_CURRENT_BINARY_DIR and CMAKE_CURRENT_SOURCE_DIR to the current working directory.

https://cmake.org/cmake/help/latest/variable/CMAKE_SOURCE_DIR.html

Upvotes: 2

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