function::returnval - Linux

Overview

function::returnval is a command used in Shell script programming to access the return value of a previously executed function. It allows you to capture and manipulate the exit status of a function and use it for further processing or decision-making within the script.

Syntax

function::returnval

There are no parameters or options for this command.

Options/Flags

This command has no options or flags.

Examples

Example 1: Capturing the return value of a function

my_function() {
    return 0  # Success
}

result=$(function::returnval my_function)

if [ $result -eq 0 ]; then
    echo "Function executed successfully."
fi

Example 2: Using the return value in a conditional statement

if function::returnval my_other_function; then
    # Do something if the function returned 0 (success)
else
    # Do something if the function returned non-zero (failure)
fi

Common Issues

• Incorrectly placed command: The command should be placed immediately after the function call, or it may capture the return value of a subsequent command.
• Mismatched parentheses: If parentheses are used around the function call, ensure they are closed properly, or the command may not work.

Integration

• With conditionals: Use function::returnval to control conditional execution flows based on the success or failure of a function.
• With scripts: Combine with other Linux commands to automate tasks or create complex scripts that rely on function return values.

Related Commands

• functions: Declare and manage shell functions.
• return: Exit a function with a specific return code.
• test: Evaluate conditions and perform actions based on their truthiness.