Accessing Android logging system
Like other Operating system, android also have a log that record when some problem occur. Using command “logcat” someone can open internal log from the system. This command is very helpfull, especially for the developer (ROM, Kernel etc) to diagnose the problem.
Access logcat from ADB
To do this, you`ll need installed ADB in your windows. And connect the device using USB Cable.
Here`s some basic command to access the log
[adb] logcat [<option>] … [<filter-spec>] …
$ adb logcat
V — Verbose (lowest priority)
D — Debug
I — Info (default priority)
W — Warning
E — Error
F — Fatal
S — Silent (highest priority, on which nothing is ever printed)
-c Clears (flushes) the entire log and exits.
-v Sets the output format for log messages
-f <filename> Writes log message output to <filename>. The default is stdout.
To create logcat output as a text file
basically you just need this command
adb logcat > filename.txt
But, you`ll be shock when open and found there`s so many log that your device have. So, you can add a filter to reduce the result.
adb logcat -v long > filename.txt
Using Logcat to find problems
case: when you try using ramdisk and the wifi wouldn`t work.
Using a basic command like above, the logcat will give you all log problem. So let`s cut the result just for error(E) or fatal(F)
adb logcat WifiStateMachine:E *:S -v long > filename.txt
note: In order to filter out anything other than what you are looking for (in this case, WifiStateMachine) you must put a *:S after your last command (i.e. WifiStateMachine:E ThemeChoose:V … … AndroidRuntime:E *:S)