adb logcat

Prints log data to the screen.

adb logcat [option] [filter-specs]

adb logcat
Notes: press Ctrl-C to stop monitor
adb logcat *:V lowest priority, filter to only show Verbose level
adb logcat *:D filter to only show Debug level
adb logcat *:I filter to only show Info level
adb logcat *:W filter to only show Warning level
adb logcat *:E filter to only show Error level
adb logcat *:F filter to only show Fatal level
adb logcat *:S Silent, highest priority, on which nothing is ever printed

adb logcat -b <Buffer>

adb logcat -b radio View the buffer that contains radio/telephony related messages.
adb logcat -b event View the buffer containing events-related messages.
adb logcat -b main default
adb logcat -c Clears the entire log and exits.
adb logcat -d Dumps the log to the screen and exits.
adb logcat -f test.logs Writes log message output to test.logs .
adb logcat -g Prints the size of the specified log buffer and exits.
adb logcat -n <count> Sets the maximum number of rotated logs to <count>. 
Notes: The default value is 4. Requires the -r option.
adb logcat -r <kbytes> Rotates the log file every <kbytes> of output.
Notes: The default value is 16. Requires the -f option.
adb logcat -s Sets the default filter spec to silent.

adb logcat -v <format>

adb logcat -v brief Display priority/tag and PID of the process issuing the message (default format).
adb logcat -v process Display PID only.)
adb logcat -v tag Display the priority/tag only.
adb logcat -v raw Display the raw log message, with no other metadata fields.
adb logcat -v time Display the date, invocation time, priority/tag, and PID of the process issuing the message.
adb logcat -v threadtime Display the date, invocation time, priority, tag, and the PID and TID of the thread issuing the message.
adb logcat -v long Display all metadata fields and separate messages with blank lines.