Info Catalog bash: Modifying Shell Behavior bash: Shell Builtin Commands

bash: Special Builtins

 
 4.4 Special Builtins
 ====================
 
 For historical reasons, the POSIX standard has classified several
 builtin commands as _special_.  When Bash is executing in POSIX mode,
 the special builtins differ from other builtin commands in three
 respects:
 
   1. Special builtins are found before shell functions during command
      lookup.
 
   2. If a special builtin returns an error status, a non-interactive
      shell exits.
 
   3. Assignment statements preceding the command stay in effect in the
      shell environment after the command completes.
 
    When Bash is not executing in POSIX mode, these builtins behave no
 differently than the rest of the Bash builtin commands.  The Bash POSIX
 mode is described in Bash POSIX Mode.
 
    These are the POSIX special builtins:
      break : . continue eval exec exit export readonly return set
      shift trap unset
 

Info Catalog bash: Modifying Shell Behavior bash: Shell Builtin Commands