*** -c 清除已有log信息
*** -b main 显示主缓冲区的log
logcat -b radio 显示无线缓冲区的log
logcat -b events 显示事件缓冲区的log
*** -f [filename] 将log保存到指定的文件中，例如 logcat -b radio -f /data/***
*** -v 设置logcat输出的格式
主要有7种:
1. brief — Display priority/tag and PID of originating process (the default format).
2. process — Display PID only.
3. tag — Display the priority/tag only.
4. thread — Display process:thread and priority/tag only.
5. raw — Display the raw log message, with no other metadata fields.
6. time — Display the date, invocation time, priority/tag, and PID of the originating process.
7. long — Display all metadata fields and separate messages with a blank lines.
比较常用的是显示时间:logcat -v time &
*** -g 查看缓冲区的大小
logcat -g main
logcat -g radio
logcat -g events