“Exit traps” can make your Bash scripts more robust and reliable (2013) (redsymbol.net)

Article summary

The article discusses the use of exit traps in Bash scripts to ensure cleanup operations are performed even when the script exits unexpectedly. This is achieved by using the EXIT pseudo-signal, which can be trapped to execute specific commands or functions when the script exits. The article provides examples of using exit traps to remove temporary files and directories, restart services, and release expensive resources. By using exit traps, Bash scripts can be made more robust and reliable.

Main themes

• Bash scripting
• Error handling
• Exit traps
• Signal handling
• Resource management
• POSIX standards

What commenters say

• Using set -e in Bash scripts can be beneficial for error handling, but it has unpredictable behavior and can cause false positives.
• Exit traps can be used to perform cleanup operations, but the behavior of the EXIT signal can vary between shells and may not always be triggered as expected.
• Some argue that using set -e without an exit handler is counterproductive, while others believe it is generally more beneficial than troublesome.
• The use of exit traps can help prevent resource leaks and ensure that temporary files are removed, but it may not be sufficient to handle all possible error cases.
• The behavior of the EXIT signal in Bash is not always consistent with POSIX standards, and may not be triggered by signals such as SIGINT or SIGKILL.
• Using separate handlers for each signal can provide more flexibility and control over the cleanup process.
• The choice of whether to use set -e or not depends on the specific use case and the level of error handling required.