def isShellBuiltin(cmd):
 if (isShellBuiltin.builtIns is None):
  isShellBuiltin.builtIns = quietRun('bash -c enable')
 space = cmd.find(' ')
 if (space > 0):
  cmd = cmd[:space]
 return (cmd in isShellBuiltin.builtIns)

def isShellBuiltin ( cmd ) : if ( isShellBuiltin . builtIns is None ) : isShellBuiltin . builtIns = quietRun ( 'bash -c enable' ) space = cmd . find ( ' ' ) if ( space > 0 ) : cmd = cmd [ : space ] return ( cmd in isShellBuiltin . builtIns )
return true if cmd is a bash builtin .