In Bash scripting, error handling is achieved through the use of exit statuses and trap commands. Exit statuses are numerical codes returned by every command upon its completion, where zero indicates success and non-zero values signify errors. To handle exceptions, we can check these statuses using conditional statements like ‘if’ or ‘case’. For instance, if a file operation fails, it returns a non-zero status which can be checked to take appropriate action.
The ‘trap’ command allows us to catch signals and execute code when they occur. We can define custom handlers for different signals including script termination (EXIT), erroneous command execution (ERR), or even user-defined ones. This provides flexibility in managing unexpected situations during script execution.
For example:
#!/bin/bash
set -e
trap "echo 'An error occurred'; exit 1" ERR
# Rest of the script...
Here, ‘set -e’ instructs bash to terminate the script if any command exits with a non-zero status. The ‘trap’ command catches this event and executes the specified echo statement before exiting.
