return status
A synonym for exit status. signal
A mechanism by which a process may be notified by the kernel of an event occurring in the system. special builtin
A shell builtin command that has been classified as special by the posix stan- dard. token
A sequence of characters considered a single unit by the shell. It is either a word or an operator. word
A sequence of characters treated as a unit by the shell. Words may not include unquoted metacharacters.