Книги
Bash
Розділ 9. Тестування та відлагодження
Виведення налагоджувальної інформації

Bash:
Виведення налагоджувальної інформації

Як це робити: 

# Echo command for simple debugging
echo "Debug: The value of variable 'x' is $x."

# Redirecting standard and error output to a file
ls -l /nonexistent/directory 2>&1 | tee debug_output.txt

# Using set -x to trace what gets executed
set -x
cp /source/file.txt /destination/
set +x

Output Sample:

Debug: The value of variable 'x' is 7.
ls: cannot access '/nonexistent/directory': No such file or directory
+ cp /source/file.txt /destination/

Поглиблене вивчення

Historically, Bash didn’t have advanced debugging tools. Simple echo statements were a primary way to output variable values and flow of control. As Bash developed, more options emerged. The set -x command outputs each command and its arguments as the script executes, which can be invaluable.

There are alternatives to Bash for debugging, such as using a formal debugger like bashdb or writing scripts in languages with better debugging support.

For implementation, note that using echo can interfere with actual output, so consider directing debug output to files or using stderr. The tee command is handy to watch the output in real-time while preserving it in a file.

Дивись також

Використання інтерактивної оболонки (REPL)