[Android] 关于Logcat我需要知道的事

# Definition of logcat

The following table describes the command line options of logcat.

Option	Description
-b <buffer>	Loads an alternate log buffer for viewing, such as events or radio. The main buffer is used by default. See Viewing Alternative Log Buffers.
-c	Clears (flushes) the entire log and exits.
-d	Dumps the log to the screen and exits.
-f <filename>	Writes log message output to <filename>. The default is stdout.
-g	Prints the size of the specified log buffer and exits.
-n <count>	Sets the maximum number of rotated logs to <count>. The default value is 4. Requires the-r option.
-r <kbytes>	Rotates the log file every <kbytes> of output. The default value is 16. Requires the -foption.
-s	Sets the default filter spec to silent.
-v <format>	Sets the output format for log messages. The default is brief format. For a list of supported formats, see Controlling Log Output Format.

# logcat 会用到的设备节点 

$ adb logcat -g
/dev/log/main: ring buffer is 256Kb (255Kb consumed), max entry is 5120b, max payload is 4076b
/dev/log/system: ring buffer is 256Kb (255Kb consumed), max entry is 5120b, max payload is 4076b

# logcat filter

我需要logcat打印处verbose,tag为ActivityManager的log。

$ adb shell logcat -s ActivityManager:V 

# logcat log to file

# logcat set the log print format

# logcat clear (flush) the entire log and exit

# logcat request alternate ring buffer ('main', 'system', 'radio', or 'events')

# logcat