For a while I've been using logcat command line tools to check Android logs. Usually, the tags of my app consist of a common prefix and the name of different sub-components (I guess that's also what most apps do). And I have about a dozen of such tags. logcat, however, does not support filtering tags using regular expressions, which is a pain! After suffering for a long time, I finally decide to tackle this.

When analyzing the logcat data from Android devices, I found that sometimes the log line get truncated, especially when it's quite long. This causes trouble because the logged information are in JSON format, which gets broken after (even one character) truncated. In this post, I'll explain how did the truncation happen, and how to fix it.