logcat

displays Android system and application logs

TLDR

View all logs

$ adb logcat

Filter by tag

$ adb logcat -s [TAG]

Filter by priority

$ adb logcat "*:[E]"

Clear log buffer

$ adb logcat -c

Output to file

$ adb logcat > [logfile.txt]

Show specific buffer

$ adb logcat -b [main,system,crash]

Format output

$ adb logcat -v [time]

logcat displays Android system and application logs. It connects to an Android device or emulator via adb and streams log messages for debugging and analysis.The tool supports filtering by tag, priority level, and buffer type. It's essential for Android development and troubleshooting.

PARAMETERS

-s tag

Filter to specific tag(s).

-b buffer

Log buffer (main, system, radio, events, crash).

-c

Clear log buffer.

-d

Dump log and exit.

-f file

Write to file.

-v format

Output format (brief, time, long, color).

-t count

Print last N lines.

-g

Get buffer size.

--pid pid

Filter by process ID.

PRIORITY LEVELS

V: VerboseD: DebugI: InfoW: WarningE: ErrorF: Fatal

CAVEATS

Requires adb connection. Buffer size limited. Old logs cleared on reboot. Some logs need root access.

HISTORY

logcat is part of the Android SDK, developed by Google. It has been the primary Android logging tool since Android's release in 2008, evolving to support more buffers and filtering options.