How get get the path of the installed executable?

Usage
1

On Linux for item Exec of .desktop, it needs the path of the executable?
Is there any better way than manully constructing as below?

set(Item_Exec ${CMAKE_INSTALL_FULL_BINDIR}>/<target_name>)
2

You can use file(GENERATE ...) and use a generator expression.

3

file(GENERATE ...) generates a file, but I want to save it to a variable instead.

4

You won’t be able to save it to a variable, because the output path is not known until generate-time, after CMakeLists.txt has already been processed.

5

So the best way is

set(Item_Exec ${CMAKE_INSTALL_FULL_BINDIR}>/<target_name>)

right?

6

In general you can’t deduce the install location of binaries/libraries from CMake. As Kyle mentioned above that variable could hold generator expressions which have to be evaluated after CMake script execution to resolve to a valid path. In addition the cmake --install command offers the --prefix flag that allows changing the install location without re-executing CMake.

Under certain conditions ( GNUInstallDirs being used ) your solution might be sufficient, but it won’t be robust.

As far as .desktop files are considered ( Desktop Entry Specification ) you can just provide the name of the executable and allow the OS to search the environments PATH variable to find the program.

1 Like
7

But the executable is in /opt/myapp/bin/, the default environment variable PATH doesn’t help.

8

I don’t have enough information to be definitive here, but one of two scenarios seems likely.

Scenario: You have standards or control over the destination system

In that case, maybe you just hardcode /opt/myapp/bin/ into *.desktop files in your package and move on.

Scenario: You have inconsistent or incomplete information about how the package is installed

Have you considered using a template file instead of a proper *.desktop file and use your packaging systems package-install-time hooks to generate (via sed perhaps?) a *.desktop file that knows the actual path as installed on the actual system? As stated above, CMake doesn’t actually know about even /opt/myapp necessarily. Many packaging systems don’t even manipulate a directory like /opt/myapp when CMake is in the picture, instead they install into a staging directory and then package that up. To be sure you’d know about the /opt/myapp path, you might need to inject that info into your *.desktop file much later in the process… for instance when the actual package installation is in progress.