Mastering the Command 'choice' (with examples)

The ‘choice’ command in Windows Command Prompt allows users to present a selection prompt to the user and return the selected choice’s index. It’s primarily used in batch scripting to provide users with options or capture user decisions during script execution, enhancing interactivity.

Use case 1: Prompt the current user to select a Y or N choice

Code:

choice

Motivation: This basic usage of the ‘choice’ command is ideal when you want to capture basic affirmative or negative input from a user. It’s common in scenarios where you seek confirmation to either proceed or abort an operation.

Explanation:

• By default, when no options are specified, the ‘choice’ command presents the user with a Y/N prompt. This defaults to presenting these two choices because they are the most common binary options in interaction.

Example Output:

[Y,N]? _

This prompts users to input either ‘Y’ or ‘N’, with the command returning an index based on their selection.

Use case 2: Prompt the current user to select a [c]hoice from a specific set

Code:

choice /c AB

Motivation: This example is useful when you want to offer users multiple specific options beyond a simple yes or no. For instance, selecting between ‘Option A’ and ‘Option B’. It is particularly beneficial in scripts or programs where multiple similar paths can be taken based on user input.

Explanation:

• /c AB: This argument specifies the set of options available. In this case, ‘A’ and ‘B’ are the possible choices the user can select from.

Example Output:

[A,B]? _

The user is prompted to choose between ‘A’ or ‘B’, and the command returns the index of the chosen option.

Use case 3: Prompt the current user to select a choice with a specific [m]essage

Code:

choice /m "Do you want to continue?"

Motivation: Tailoring the message provides context or additional information to the user, guiding them on what their selection implies. This usage is particularly useful for clarity when the default ‘Y/N’ options aren’t self-explanatory regarding the operation’s nature.

Explanation:

• /m "Do you want to continue?": The argument allows you to display a custom message alongside the choices. It helps inform the user about the implications of their choice in a way that is more descriptive than default prompts.

Example Output:

Do you want to continue? [Y,N]? _

The user sees a clear message prompting them to decide whether to proceed by choosing ‘Y’ or not by choosing ‘N’.

Use case 4: Prompt the current user to select a [c]ase-[s]ensitive [c]hoice from a specific set

Code:

choice /cs /c Ab

Motivation: Case sensitivity becomes crucial when uppercase and lowercase options represent different choices, or when commands should adhere strictly to casing for the sake of clarity or convention in script responses.

Explanation:

• /cs: This argument enforces case sensitivity, meaning ‘A’ and ‘b’ are different options.
• /c Ab: Specifies the choices are ‘A’ and ‘b’, differentiation of which requires case sensitivity.

Example Output:

[A,b]? _

Users must choose from ‘A’ or ‘b’, and are made aware that case matters for this choice.

Use case 5: Prompt the current user to select a choice and prefer the [d]efault choice in a specific [t]ime

Code:

choice /t 5 /d N

Motivation: In scenarios where an automatic choice is needed after a given amount of time (like when a script needs to run unattended), setting a timeout and default choice ensures that processes continue rather than stall due to user inaction.

Explanation:

• /t 5: Sets a timeout of 5 seconds. If the user doesn’t make a choice within this time, a default option will be automatically selected.
• /d N: Specifies ‘N’ as the default choice in the event the timeout elapses.

Example Output:

[Y,N]? _ (Automatically selects 'N' after 5 seconds)

The command automatically selects ‘N’ if the user doesn’t respond within 5 seconds.

Use case 6: Display help

Code:

choice /?

Motivation: Viewing the help documentation is essential for both beginners and experienced users to understand the command’s functionality fully, as well as to explore potential options or arguments that can be paired with the command for varied use cases.

Explanation:

• By using /?, the user can access in-line documentation directly from the console, which details all the arguments and their usage for the ‘choice’ command.

Example Output:

CHOICE [/C choices] [/N] [/CS] [/T timeout /D choice] [/M text]
Description: This displays on-screen command help for how to use the 'choice' command, detailing each available parameter.

Conclusion:

The ‘choice’ command is a versatile tool in Windows scripting for capturing and processing user decisions based on presented options. Understanding its full scope of uses—from simple binary choices to complex sets of options and case-sensitive scenarios—enables more dynamic and interactive scripts. By leveraging this command, scripts can cater to varying levels of interaction needed for different use cases.