Gravity update: Handle color escape sequences

[catch-error]

What does this PR aim to accomplish?:

Currently when running gravity update, the color escape sequences used by the shell script are printed literally on the web gui:

  [�[1;32m✓�[0m] DNS resolution is available

  [i] Neutrino emissions detected�[0m...
  [�[1;32m✓�[0m] Pulling blocklist source list into range
  ...

This should be the matching real colors instead.

How does this PR accomplish the above?:

The patch checks each line fragment for the existance of a pattern that represents an (ANSI) color code escape sequence and substitutes it with a fitting HTML code.

To preserve color coding also when removing line(s) because of OVER escape sequences, the code is changed from using .text() to .html().

Link documentation PRs if any are needed to support this PR:

N/A

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[yubiuser]

Interesting, what browser do you use?
I don't see colors, but the escape sequences are printed as they should as symbols.

[rdwebdesign]

I just checked and also don't see color codes.
I think they should be stripped before data is sent to the browser. Actually this is how v5 works.

[catch-error]

I tried it on Chrome & Safari on MacOS, Chrome & Firefox and Windows & Linux. Some subtle differences how the actual escape character is printed, but the rest looks pretty much the same on all systems. I have been working with 6.0 code a lot lately, so maybe screwed something up on my DEV VM.

[rdwebdesign]

Did you change /opt/pihole/COL_TABLE file?

I was able to reproduce your issue only when I edit this file to force the use of colors even when the command is not executed from a terminal.

Output with modified COL_TABLE:

Output with original COL_TABLE:

[catch-error]

No. But I have the WEBCALL always set for pihole. This dates back quite a bit and I simply forgot about it. When it was introduced, it had been a convenient way to always enable colors in a code independent way (with the side effect of also having them in the web interface). And since this is still in the 6.0 code, it just carried over.

Is there a technical reason for not wanting gravity output colors in the web interface? Iirc WEBCALL has been introduced specifically for piholeDebug.sh (and is still in pihole code today, although the debug option has been removed from the 6.0 web interface), but never extended to cover also the gravity output.

[rdwebdesign]

Iirc WEBCALL has been introduced specifically for piholeDebug.sh

Actually, WEBCALL was introduced in 2017, to be used by /var/www/html/scripts/php/debug.php (the -w flag, line 55).
It was introduced specifically to replace Carriage Return (\r) with newline (\n) character before send the text to the web interface, not to allow colors.

At that time, the debug log in the web interface didn't had colors, because using them resulted in a broken output (like you are seeing).

Later (in 2022), I changed the COL_TABLE code to allow color in the web interface, but this only worked because I also created a PHP function to translate ANSI color codes into HTML+CSS.

This was created to fix the Debug Logs uploaded via web interface. Before that, the debug logs generated via web interface didn't had colors and it was harder for us to identify certain issues.

Now there is no web interface debug log in v6, so there is no need for this flag anymore. We just forgot to remove the unused code from COL_TABLE. Any terminal with the capacity to show colors will always use the colors without this flag.

Gravity Update was never showed in colors in v5 web interface (there was never a PHP function to translate them).

[catch-error]

I wrote my own PHP code for that, though never submitted it. Still I‘d like to see colors also being included in the web interface - it just helps.