logcat_monitor

Flutter plugin to monitor the stream of system messages, stack traces etc using logcat command-line tool.

NOTE: This plugin fetches logs only on Android Devices presently.

how to use

1. Create a function to consume the logcat messages

  void _mylistenStream(dynamic value) {
    if (value is String) {
      _logBuffer.writeln(value);
    }
  }

2. Register your function as a listener to get logs then use it in anyway within your app.

    LogcatMonitor.addListen(_mylistenStream);

3. Start the logcat monitor passing the filter parameters as defined in logcat tool.

    await LogcatMonitor.startMonitor("*.*");

Installation

Need permission in AndroidManifest.xml:

<uses-permission android:name="android.permission.READ_LOGS" />

https://pub.dev/packages/logcat_monitor/install

example

Follows a screenshot of example code in example folder.

Here we use a StringBuffer to store the messages and display them in the log screen.

under the hood

The LogcatMonitorPlugin runs event/method channel handlers in UI-thread and the logcat process monitor in a background thread as recomended by Google to not block the UI interface.

logcat filter options

from logcat -h:

filterspecs are a series of 
  <tag>[:priority]

where <tag> is a log component tag (or * for all) and priority is:
  V    Verbose (default for <tag>)
  D    Debug (default for '*')
  I    Info
  W    Warn
  E    Error
  F    Fatal
  S    Silent (suppress all output)

'*' by itself means '*:D' and <tag> by itself means <tag>:V.
If no '*' filterspec or -s on command line, all filter defaults to '*:V'.
eg: '*:S <tag>' prints only <tag>, '<tag>:S' suppresses all <tag> log messages.

Examples:

• *.* show ALL tags and priorities.
• flutter,LogcatMonPlugin,S:* show flutter and LogcatMonPlugin and suppresses all others.