sexy-bash-prompt and 'set -x'

[rpdelaney]

set -x is a familiar shell option for debugging. Usually, I like to set it from the command-line before running a script to debug, as is common practice. But this causes lots of unwanted debugging output from sexy-bash-prompt because the functions it invokes also return debugging output.

Would it be reasonable to add a handler to each function that checks for this flag, disables it, and then restores it before exit? I could submit a pull request to that effect.

[twolfson]

It feels like this is not the responsibility of sexy-bash-prompt. Why are you setting a global set -x flag? Is there a problem with setting it inside your script?

For what it's worth, if someone is setting a global flag, then they might actually want debug output from sexy-bash-prompt as well as everything else.

[rpdelaney]

Setting it inside the script is not a 'problem', per se: it's just inconvenient.

For people who want to debug the prompt, I suppose we could support another env var like SEXY_BASH_PROMPT_DEBUG. Or they could edit the script ;)

[twolfson]

Yea, but that feels like we are adding more workarounds to the problem.

I added a set -x to my terminal and only saw 2 invocations:

Then, I moved my prompt to use these set +x flags:

# Define the sexy-bash-prompt
PS1="\[$sexy_bash_prompt_user_color\]\u\[$sexy_bash_prompt_reset\] \
\[$sexy_bash_prompt_preposition_color\]at\[$sexy_bash_prompt_reset\] \
\[$sexy_bash_prompt_device_color\]\h\[$sexy_bash_prompt_reset\] \
\[$sexy_bash_prompt_preposition_color\]in\[$sexy_bash_prompt_reset\] \
\[$sexy_bash_prompt_dir_color\]\w\[$sexy_bash_prompt_reset\]\
\$(set +x && sexy_bash_prompt_is_on_git && \
  echo -n \" \[$sexy_bash_prompt_preposition_color\]on\[$sexy_bash_prompt_reset\] \" && \
  echo -n \"\[$sexy_bash_prompt_git_status_color\]\$(sexy_bash_prompt_get_git_info)\" && \
  echo -n \"\[$sexy_bash_prompt_git_progress_color\]\$(sexy_bash_prompt_get_git_progress)\" && \
  echo -n \"\[$sexy_bash_prompt_preposition_color\]\")\n\[$sexy_bash_prompt_reset\]\
\[$sexy_bash_prompt_symbol_color\]$(set +x && sexy_bash_prompt_get_prompt_symbol) \[$sexy_bash_prompt_reset\]"

But there are still echos coming from the prompt.

[twolfson]

Ah, never mind. I went into a git directory and now see al the noise.

[twolfson]

I did some research but am going to step away for a bit. New info I found out:

• set -o xtrace is an alias for set -x
• We can retrieve current settings (e.g. xtrace is enabled via set -o)
• We can redirect set -x output via BASH_XTRACEFD

(all info via man bash)

[twolfson]

Alright, back. I am still on the fence about this. Can we research what other libraries do for this scenario?

[rpdelaney]

I'm looking into it.

[abhijit86k]

When I need to run anything with +x I run it like this: $ set -x; comand -arg1 -arg2 -arg3; set +x;

clean terminal again.

[rpdelaney]

Yeah good enough for me.