In Unix, the command to enable execution permission for file "mylife" by all…

Answer: Use chmod a+x mylife (other equivalent forms listed below also work).

• chmod a+x mylife — adds execute permission for all (a = user, group, others).

• chmod ugo+x mylife — explicitly lists user (u), group (g) and others (o); +x adds execute permission.

• chmod +x mylife — when no class is specified, chmod applies the change to all classes (equivalent to a+x).

Note: Use lowercase 'chmod' and do not put spaces between the class, operator and mode. For example, write chmod a+x mylife rather than Chmod a + X mylife.