. file [ arg ... ]
       Read commands from file and execute them in the current shell en-
       vironment.

       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 con-
       taining 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  para-
       meters;  the old positional parameters are restored when the file
       is done executing.  However, if no arguments are given, the posi-
       tional 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.