for_file var filename code
          This procedure implements a loop over the contents of a
          file.   For  each  line in filename, it sets var to the
          line and executes code.

          The break and continue commands work as with foreach.

          For example, the command

               for_file line /etc/passwd {echo $line}

          would echo all the lines in the password file.

          This procedure is provided by Extended Tcl.