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Filter & Regex Editor

LogViewer gives you complete control over how filters match log messages, how they are colored, and how complex your query expressions can be.

Filter Editor

Filter Editor

When creating or editing a filter (double-click a filter or right-click and choose Edit), you can configure:

  • Filter Name: A descriptive label for the filter (e.g. ActivityManager, Fatal Exception, or RIL Requests). If left blank or simple, the query itself can serve as the label.
  • Color Picker: Choose a distinct background or foreground color for matching lines. Assigning distinct hues (for example: red for errors, cyan for network, yellow for warnings) makes scanning logs effortless.
  • Case Sensitivity: Toggle whether matching respects letter casing.
  • Regex Toggle: Enable or disable regular expression parsing.

Integrated Regex Editor

Creating complex regular expressions can be error-prone. LogViewer includes an interactive Regex Editor to test and preview queries before saving:

Regex Editor

Key Features

  • Live Match Highlighting: Type your expression in the Regex field, and sample text in the test area below will highlight matching segments in real time.
  • Syntax Error Feedback: If your regular expression has invalid syntax, the input field turns red immediately to warn you before saving.
  • Test with Real Logs: Paste actual log lines from your bugreport into the test area to verify that your pattern catches edge cases.

Common Android Regex Patterns

Here are several useful regular expression patterns commonly used in LogViewer:

Pattern Target Matches
(?i)fatal\|exception\|crash Any line containing fatal errors, uncaught exceptions, or crash traces (case-insensitive).
\bActivityTaskManager\b Specific Android framework system service tags.
Displayed\s+com\.example\.app App launch completion and cold-start latency measurements.
ANR in\s+ Application Not Responding (ANR) trace triggers.
(?<=pid\s)\d+ Process ID number extraction.