Is there a way to filter special characters in formatted messages?

[gh-andre]

Consider this code, where ABC\nXYZ comes from some 3rd-party component, like an error message with a call stack dump.

  logi("External text: {:s}", "ABC\nXYZ");
  logi("External text: {:s}", "ABC XYZ");
  fmtlog::poll();

This will produce log lines that cannot be processed by log handlers because it contains arbitrary characters.

18:04:44.371584 log_test.cc:23   INF[4812  ] External text: ABC
XYZ
18:04:44.789673 log_test.cc:24   INF[4812  ] External text: ABC XYZ

Is there a way to set up some callback where the message can be modified?

I'm looking for a callback similar to fmtlog::setLogCB, but which would allow to return a replacement for msg, which would be used instead, but only if some indicator says that it was changed, like a \n was found.

Thanks

[gh-andre]

I ended up adding a callback to rewrite formatted log messages. Here's the fix, if anyone is interested.

github.com/gh-andre/fmtlog/commit/616c8ec7

See README in the patch branch for more information and a working example in test/log_test.cc.

https://github.com/gh-andre/fmtlog/tree/v2-2-1-patches#changes