BASH BUILTIN COMMANDS        Unless  otherwise  noted, each builtin command documented in this section as        accepting options preceded by -  accepts  --  to  signify  the  end  of  the        options.  The :, true, false, and test builtins do not accept options and do        not treat -- specially.  The exit, logout, break, continue, let,  and  shift        builtins accept and process arguments beginning with - without requiring --.        Other builtins that accept arguments but  are  not  specified  as  accepting        options  interpret arguments beginning with - as invalid options and require        -- to prevent this interpretation.        : [arguments]               No effect; the command does nothing beyond  expanding  arguments  and               performing any specified redirections.  A zero exit code is returned. 
 
         .  filename [arguments]        source filename [arguments]               Read and execute commands from filename in the current shell environ‐               ment and return the exit status of the  last  command  executed  from               filename.   If  filename does not contain a slash, file names in PATH               are used  to  find  the  directory  containing  filename.   The  file               searched  for  in  PATH  need not be executable.  When bash is not in               posix mode, the current directory is searched if no file is found  in               PATH.   If  the  sourcepath  option  to  the shopt builtin command is               turned off, the PATH is not searched.  If any arguments are supplied,               they  become  the  positional  parameters  when filename is executed.               Otherwise the positional parameters are unchanged.  The return status               is  the  status of the last command exited within the script (0 if no               commands are executed), and false if filename is not found or  cannot               be read.   |