logcat
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]
SYNOPSIS
logcat [options] [filter...]
DESCRIPTION
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: Verbose
D: Debug
I: Info
W: Warning
E: Error
F: 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.
SEE ALSO
adb(1), dmesg(1), journalctl(1)
