. file [ arg ... ]
       Read  commands  from  file and execute them in the current shell
       environment.

       If file does not contain a slash, or if PATH_DIRS  is  set,  the
       shell  looks  in  the  components of $path to find the directory
       containing file.  Files in the current directory  are  not  read
       unless  `.'  appears  somewhere  in  $path.   If  a  file  named
       `file.zwc' is found, is newer than file,  and  is  the  compiled
       form  (created with the zcompile builtin) of file, then commands
       are read from that file instead of file.

       If any arguments arg  are  given,  they  become  the  positional
       parameters;  the old positional parameters are restored when the
       file is done executing.  However, if no arguments are given, the
       positional  parameters  remain those of the calling context, and
       no restoring is done.

       If file was not found the return status  is  127;  if  file  was
       found  but  contained  a  syntax error the return status is 126;
       else the return status is the exit status of  the  last  command
       executed.
