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Comment by pzmarzly | Hacker News Reader

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pzmarzly

Another useful flag is -x, which enables tracing (Bash will print each command before executing it).

You can disable it again with set +x (same goes for +e, +u and afaik +o pipefail)

Also, please use shellcheck - https://www.shellcheck.net/

EDIT: Also, please don't modify scripts while they are running.

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Specifying PS4 when using the -x flag can be even more helpful while debugging. The variable PS4 denotes the value is the prompt printed before the command line is echoed when the -x option is set and defaults to : followed by space.

A number of useful debugging tips are listed at <https://wiki.bash-hackers.org/scripting/debuggingtips>.

Here's a workaround for modifying scripts while they are running; it works because function bodies are read and parsed entirely when they are defined.

  main() {
    script goes here
    exit
  }
  main "$@"

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