understanding logcat output when written to file

问题

I have a log cat which is outputted to a text file but can't find anything on what each part means. For example, I have the following:

W/Trace   (  857): Unexpected value from nativeGetEnabledTags: 0

E/ActivityThread(  565): Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d35408 that was originally bound here

E/ActivityThread(  565): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d35408 that was originally bound here

E/ActivityThread(  565):    at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)

I'm not sure what each part means I assume W/ means its a warning and E/ means its an error. But not sure the text is after the slash. I'm also not sure what the number is in the brackets.

Thanks for any help you can provide.

回答1:

This can be easily understood by simply comparing the output of logcat with that displayed in DDMS. Here's an example:

Logcat output:

E/QC-DSS-LIB(   74): unrecognized ifi_index 15
D/wpa_supplicant(19367): RTM_NEWLINK: operstate=0 ifi_flags=0x11003 ([UP][LOWER_UP])
D/wpa_supplicant(19367): RTM_NEWLINK, IFLA_IFNAME: Interface 'eth0' added
D/wpa_supplicant(19367): Wireless event: cmd=0x8c02 len=27
D/wpa_supplicant(19367): RTM_NEWLINK: operstate=0 ifi_flags=0x11003 ([UP][LOWER_UP])
D/wpa_supplicant(19367): RTM_NEWLINK, IFLA_IFNAME: Interface 'eth0' added
D/wpa_supplicant(19367): Wireless event: cmd=0x8c02 len=33
D/WifiStateTracker(  123): Reset connections and stopping DHCP

DDMS screenshot:

Analysis of the first line from the screenshot:

• "E" is the log level
• QC-DSS-LIB is the tag
• "74" is the Process ID

If you wish to get the timestamp also from logcat, use the -v switch like this:

logcat -v time

which would give an output in this format:

02-16 09:58:21.446 E/QC-DSS-LIB(   74): unrecognized ifi_index 15

回答2:

What you are seeing is a stacktrace. AT the top you have the last known place the app was running at. You have at line 857, you forgot to cast or doing something else there.

The text after the hash are just the error or warning messages like you correctly assumed. The number in the bracket is the line.

来源：https://stackoverflow.com/questions/14865538/understanding-logcat-output-when-written-to-file