Sets the file path to use as the stdout for spawned processes.
If path is null then any previously given path is unset.
The file will be created or truncated when the process is spawned, as would be the case if using '>' at the shell.
You may not set a stdout file path if a stdout fd is already set or if the launcher flags contain any flags directing stdout elsewhere.
This feature is only available on UNIX.
| this | |
| path |
a filename or null |