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.