システムログは、adb shell やターミナルエミュレータ(要root権限)で logcat コマンドを実行すること確認できる。
$ logcat --------- beginning of /dev/log/system I/Vold ( 910): Vold 2.1 (the revenge) firing up D/Vold ( 910): Volume sdcard state changing -1 (Initializing) -> 0 (No-Media) D/Vold ( 910): Volume usb0 state changing -1 (Initializing) -> 0 (No-Media) D/Vold ( 910): Volume usb1 state changing -1 (Initializing) -> 0 (No-Media) D/Vold ( 910): Volume usbdisk state changing -1 (Initializing) -> 0 (No-Media) D/Vold ( 910): Volume sdcard state changing 0 (No-Media) -> 1 (Idle-Unmounted) W/Vold ( 910): Duplicate state (1) W/Vold ( 910): No UMS switch available I/SystemServer( 981): Entered the Android system server! I/SystemServer( 981): Entropy Service I/SystemServer( 981): Power Manager I/SystemServer( 981): Activity Manager I/ActivityManager( 981): Memory class: 32 I/SystemServer( 981): Telephony Registry I/SystemServer( 981): Package Manager I/Installer( 981): connecting...
左の大文字アルファベットはメッセージの重要度/緊急度(priority)を意味する。
- V: Verbose (重要でない)
- D: Debug (デバッグ時に役に立つかもしれない)
- I: Info (エラーでは無いが重要)
- W: Warn (エラーでは無いが、今後何らかの問題を引き起こすかもしれない)
- E: Error (何らかの問題がある)
- F: Fatal (致命的な問題がある)
logcat のヘルプ
# logcat -h
unknown option -- hUnrecognized Option
Usage: logcat [options] [filterspecs]
options include:
-s Set default filter to silent.
Like specifying filterspec '*:s'
-f <filename> Log to file. Default to stdout
-r [<kbytes>] Rotate log every kbytes. (16 if unspecified). Requires -f
-n <count> Sets max number of rotated logs to <count>, default 4
-v <format> Sets the log print format, where <format> is one of:
brief process tag thread raw time threadtime long
-c clear (flush) the entire log and exit
-d dump the log and then exit (don't block)
-t <count> print only the most recent <count> lines (implies -d)
-g get the size of the log's ring buffer and exit
-b <buffer> request alternate ring buffer
('main' (default), 'radio', 'events')
-B output the log in binary filterspecs are a series of
<tag>[:priority]
where <tag> is a log component tag (or * for all) and priority is:
V Verbose
D Debug
I Info
W Warn
E Error
F Fatal
S Silent (supress all output)
'*' means '*:d' and <tag> by itself means <tag>:v
If not specified on the commandline, filterspec is set from ANDROID_LOG_TAGS.
If no filterspec is found, filter defaults to '*:I'
If not specified with -v, format is set from ANDROID_PRINTF_LOG
or defaults to "brief"
※ -h オプションは logcat には無い...
