CPUPROFILESDIR

CPUPROFILESDIR is an environment variable used by a subset of CPU profiling tools to indicate where to store generated profiling data. It is not part of a universal standard; its behavior depends on the specific toolchain in use. When a profiler that recognizes this variable is launched with CPUPROFILESDIR set, the tool may create the directory (if it does not exist) and write profiling data files into that location. These files typically contain information such as call stacks, timing, and CPU usage for the program being profiled, and may use a .cpuprofile extension in some workflows.

Usage of the variable is straightforward: set it before starting the application or profiler. In Unix-like environments, you would use a command such as export CPUPROFILESDIR=/path/to/cpu_profiles. In Windows, you would use set CPUPROFILESDIR=C:\cpu_profiles. Depending on the tool, you might need to create the directory manually or the tool may create it automatically.

Compatibility and scope: Because CPUPROFILESDIR is not standardized, not all profilers honor it. If a tool does not mention support for this environment variable, it may require an explicit output directory flag or rely on a default location. When in doubt, consult the specific tool’s documentation or help output to determine how profiling data should be configured and where it will be written.

Best practices: Use a dedicated, writable directory for profiling data, and consider organizing outputs by run with distinct subdirectories. Implement a retention policy to purge old profiles to manage disk space, and ensure the profiling process has the necessary permissions to write to the chosen location.

See also: CPUPROFILE, CPU profiling, profiling workflows, Chrome DevTools CPU profiling.