CONFIRM asks the user for Yes/No confirmation,
Used in a BAT or BTM file to set errorlevel to 0 if user answers Y,
or 1 if N.
  @echo off
  echo Do you really want to do this dangerous thing?
  confirm.com
  If ERRORLEVEL 1 GoTo NO
  GoTo YES
Note, no parameters or messages go on the confirm command line itself.
There are two versions included, both with source: ASSEMBLER version
confirm.com that works in
DOS/W3.1/W95/W98/Me/NT/W2K/XP/W2K3/Vista/W7-32/W8-32 and a 32-bit C
version confirm.exe that works in
W95/W98/Me/NT/W2K/XP/W2K3/Vista/W7-32/W7-64/W8-32/W8-64 Normally you would
use the confirm.com version except for Windows 7 64-bit.  It is smaller
and faster.
However, the confirm.exe version also looks for SET
confirm=y/n/yes/no/Y/N/YES/NO.  If it sees it, the user does not need to
key anything.  It acts as if the user had hit the Y or N.  This allows you
to control the way confirm works in a bat/btm file you call.  You can make
the confirm.exe effectely disappear, or automate the response.  Set
confirm= turns the feature off makes confirm behave normally.
It does not automatically revert to confirm=.
SET confirm=Y does NOT mean "engage the confirm.exe utility".  It means
"automatically answer the confirm with Y".
Why the traffic warning sign, yellow triangle surrounding an exclamation
mark?  It suggests danger and caution, the situatinos where confirm is
used.