Bash 디버깅 모드

12 Sep 2023

linux

When working with Bash scripts in Linux, debugging can be a crucial part of the development process. Bash provides a built-in debugging mode that allows you to trace the execution of your script and identify any errors or issues.

Activating Bash 디버깅 모드

To activate the debugging mode in Bash, you need to add the -x option to your script. This option tells Bash to print each command before executing it. This can help you understand the flow and identify the exact point where an error occurs.

You can activate the debugging mode by adding the following line at the beginning of your script:

#!/bin/bash -x

Benefits of 디버깅 모드

By enabling 디버깅 모드, you gain the following benefits:

Line-by-line trace: The debugging mode prints each command before executing it, allowing you to see the order in which the commands are executed. This can help you identify logic errors or incorrect command sequences.
Variable value tracking: In 디버깅 모드, you can see the values of variables as they change throughout the execution of the script. This is particularly useful for troubleshooting issues related to variable assignments or manipulations.
Command expansion: 디버깅 모드 also displays the expansion of variables and command substitutions. This helps you ensure that the correct values are being used and can help pinpoint issues with variable substitutions.
Command exit status: With 디버깅 모드, you can view the exit status of each command. This allows you to identify whether a command executed successfully or encountered an error.

Example Usage

Here’s an example of a Bash script with 디버깅 모드 activated:

#!/bin/bash -x

# Declare variables
NAME="John"
AGE=30

# Print a greeting
echo "Hello, $NAME!"

# Validate age
if [ $AGE -lt 18 ]; then
  echo "You are too young!"
else
  echo "You are old enough!"
fi

When you run this script, you will see the full trace of the execution, including the expansion of variables and the exit status of each command. This can be immensely helpful in understanding the script’s behavior and identifying any errors.

Conclusion

Bash’s 디버깅 모드 is a powerful feature that allows you to trace the execution of your scripts and identify errors or issues more easily. By activating 디버깅 모드, you gain insights into the order of command execution, variable values, command expansion, and command exit status. This helps you streamline your development process and ensure the accuracy and reliability of your Bash scripts.