One reason for using batch files is to streamline the user's workflow by handling complex command sequences automatically, operating behind the scenes. To suppress the echoing of commands to the screen, which could confuse the user, many batch files begin with an echo off command. Although this suppresses the echoing of the commands, it doesn't suppress any output that might result from those commands. Most of the remaining output can be suppressed by adding >NUL at the end of every command in the batch file that produces output, to redirect the output from the command to an imaginary device called NULthe bit bucket I've mentioned in previous columns.
OCLC Micro – Emerald Publishing
Published: Mar 1, 1987