ctest:tldr:0b190
ctest: Run all tests defined in the CMake project, executing 4 jobs at a time in parallel.
$ ctest -j${4} --output-on-failure
try on your machine
The command you provided is a command line instruction using the "ctest" tool. Here is the breakdown of the command:
- "ctest" is a CMake test driver program used to run tests in the CMake build system.
- "-j${4}" option specifies the number of parallel test jobs to run. The "${4}" specifies a variable (let's call it 'var4') that should be substituted with its value during command execution. The value of 'var4' can be passed as a command-line argument.
- "--output-on-failure" option instructs ctest to display the output (including the test's standard output and standard error) only when a test fails. By default, ctest only shows output for failing tests and warnings.
So, when this command is executed, ctest will run tests in parallel (the number of parallel jobs will depend on the value assigned to the variable '4'), and it will show the test output only if a test fails, providing more information about the failure.
This explanation was created by an AI. In most cases those are correct. But please always be careful and
never run a command you are not sure if it is safe.