Debug Mode (set -x)
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Debug Mode (set -x)
set -x makes Bash print each command with its expanded arguments before running it, which is invaluable for tracing exactly what a script does. set +x turns it back off. Debug tracing is usually enabled temporarily around a suspicious section rather than for an entire large script.
Note: Wrap only the suspicious section in set -x / set +x rather than tracing the whole script, to keep the output readable.
Example: Debug Mode (set -x)
#!/bin/bash
echo "Before debug mode"
set -x
x=5
y=$((x * 2))
set +x
echo "After debug mode, y=$y"Login to try C/C++/Java/PHP code in the editor
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Chapter Quiz — Complete all 12 topics to unlock
0/12 topics done
Complete these topics first:
- Exit Codes and Checking $? Correctly
- set -e and set -u
- Error Handling
- set -e (Exit on Error) and Its Gotchas
- Logging
- set -u (Undefined Variables) and set -x (Trace Mode)
- Script Arguments with getopts
- trap ERR for Custom Error Handling
- Debug Mode (set -x)
- Writing a Custom Error/die Function
- Portability
- Validating Script Input and Arguments