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. 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.  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.