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- Text File _query.rem
-
-
-
- QUERY.COM
-
- The purpose of the QUERY utility is to allow the user of a Batch File to answer
- a prompting message or comment with a yes/no (or ESC) response. The QUERY
- utility then sets the system "errorlevel" parameter so that a subsequent IF
- subcommand in the Batch File can branch accordingly. QUERY will optionally
- execute some display formatting commands before it displays a prompt string.
-
-
- The format of the QUERY command line is shown below, with the usual convention
- that items in brackets [ ] are optional.
-
- QUERY [ / [ c1 [ c2 ... ] ] / ] [ string ]
-
-
- where c1, c2, etc are optional formatting commands enclosed in slashes.
- These commands are executed in the order they are encountered, before the
- string is displayed. The one-letter commands that are currently supported
- include the following:
-
-
- B or b Beep the console
-
- L or l Skip one line
-
- D or d Display a "delimiting" border across the screen.
-
-
- After the "slash" commands are executed, the string is displayed. If no
- slashes precede the string, the leading blanks and tabs are discarded. If
- slashes were present, then all characters after the second slash are
- displayed.
-
- The only constraint on the string's characters is that "<", "|", and ">" must
- not be used in the string.
-
- Following the string, a reverse video "box" is displayed. When the user
- responds with a keystroke, the box "un-reverses" and the character is
- displayed.
-
- QUERY then returns to the Batch File with the errorlevel parameter set as
- follows:
-
-
-
-
- errorlevel = 2 if user typed Esc key
-
- errorlevel = 1 if user typed Y or y
-
- errorlevel = 0 if user typed N or n
-
- If any other key is typed, the console is beeped, a message is displayed, and
- QUERY waits for another keystroke.
-
- Let's return to the Batch File to show some examples. The first example shows
- the simplest use of QUERY and how to test the errorlevel code with subsequent
- IF subcommands. We'll first display the command lines in these comments, and
- then we will return to the Batch File and execute the same command lines.
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- Here are the command lines:
-
- query Is this example easy (y/n) ?
- if errorlevel 2 goto esc_key
- if not errorlevel 1 goto n_key
- echo You typed a "Y" or a "y"
- goto continue
- :n_key
- echo You typed a "N" or an "n"
- goto continue
- :esc_key
- echo you pressed the Esc key
- :continue
-
- Examine the command lines (remember that the logic of the "IF" test is "greater
- than or equal to" and the "IF NOT" test, "less than" ), then strike a key and
- we'll execute the sequence.
- (e.g. DOS 2.0 = 2