def executable(cls): if cls._executable is None: cls._executable = Shell.find_executable('csh') return cls._executable
def executable(cls): if cls._executable is None: cls._executable = Shell.find_executable('tcsh') return cls._executable
def executable(cls): if cls._executable is None: cls._executable = Shell.find_executable('powershell') return cls._executable
def executable(cls): return Shell.find_executable('sh')