select-default-iwrap

select-default-iwrap [-p <prompt>] [-d <default_value>] <item1> [<item2> ...]

This synopsis illustrates a common way such a function might be invoked within a Bash script, providing a custom prompt, an optional default selection, and a list of choices. Actual function implementations may vary in their arguments and behavior.

-p <prompt>
    Optional. Specifies the introductory message displayed to the user before presenting the choices. For example, 'Please choose an option:'.

-d <default_value>
    Optional. Defines the value that will be returned if the user presses Enter without typing a selection. This value should typically correspond to one of the provided items.

<item1> [<item2> ...]
    The list of options from which the user can choose. Each item will be displayed with a corresponding number, allowing the user to select by entering the number.

The term "select-default-iwrap" does not refer to a standalone Linux command with a dedicated man page, but rather to a common and robust shell scripting pattern. It is typically implemented as a Bash function designed to enhance the built-in Bash select command. This pattern aims to provide a more user-friendly and fault-tolerant interactive menu experience.

Key features commonly integrated into a "select-default-iwrap" implementation include:

• Offering a default choice if the user simply presses Enter, making interactions quicker.
• Performing input validation to ensure the user's selection is within the valid range of options.
• Reprompting the user until valid input is received, preventing script errors from bad input.

This pattern abstracts away the complexities of manual input handling and error checking, making script interaction reliable and intuitive.

It is crucial to understand that "select-default-iwrap" is a conceptual scripting pattern, not a pre-installed executable command like ls or grep. Its implementation details can vary significantly across different scripts or developers. It relies heavily on the Bash shell's select built-in and other Bash-specific features, meaning it is primarily applicable in Bash scripting environments and may not be portable to other shells without modifications. Ensure that the default value, if provided, accurately corresponds to an expected item for proper behavior.

A common implementation of a select-default-iwrap function involves an outer loop that continues until valid input is received. Inside this loop, the select built-in command is used to display the numbered options. The shell variable PS3 is often set to customize the prompt displayed by select (e.g., 'Make your choice #? '). After the user enters input, the REPLY variable holds the entered string. The script then checks if REPLY is empty (indicating the default should be used) or if it's a valid number corresponding to an existing option. Error messages are displayed for invalid input, and the loop reiterates, prompting the user again.

Although not a standalone command, a typical use of a function implementing this pattern in a Bash script would look similar to this:

#!/bin/bash

# Assume 'select-default-iwrap' function is defined here or sourced from a library.
#
# Example function definition (simplified):
# select-default-iwrap() {
# local prompt="${1:-'Select an option'}"
# local default_val="$2"
# shift 2
# local options=("$@")
# # ... implementation logic with 'select' and validation ...
# # return selected value
# }

echo "Configuring application..."

CHOICE=$(select-default-iwrap -p "Choose an action" -d "View" "Edit" "View" "Delete" "Exit")

echo "
You chose: $CHOICE"

case "$CHOICE" in
"Edit") echo "Opening editor...";;
"View") echo "Displaying data...";;
"Delete") echo "Deleting records...";;
"Exit") echo "Exiting...";;
*) echo "Invalid choice or default action.";;
esac

This example assumes a function named select-default-iwrap is defined and returns the chosen value, which is then assigned to the CHOICE variable for further script logic.

bash(1), read(1)