[Article]Workaround for grep and Logcat, dmesg, and last_kmsg on Windows

gistfile1.txt

In this article, I will explain some of the confusions that may occur whilst using grep in logcat, dmesg, kmsg and last_kmsg on different platforms,mainly between Unix(Linux based such as ubuntu, linux mint, fedora, BSD based such as netbsd, freebsd, and even Mac) and Windows(Windows XP, Windows Vista, Windows 7, Windows 8 and etc). 

[SIZE="4"][B]Requirements[/B][/SIZE]:
[LIST=1]
[*]Known about the existence of logcat, dmesg, kmsg, and last_kmsg and have tried logging it at least once
[*]Know some basic knowledge of batch/bash(cmd/terminal)
[*]Using Windows OS(The problem only lies on Windows, so if you're using Mac or Linux then you're fine)
[/LIST]

Although this is a rather technical article, but I will make it as simple as possible for all of the users to understand :)

Sometimes, I will see some of the developers will issue similar to this:

[SIZE="4"][B]Log Commands with Grep[/B][/SIZE]
[QUOTE]
[B]Logcat[/B]:
adb logcat | grep 'htc'

[B]Dmesg[/B]:
adb shell dmesg | grep 'mp_decision'

[B]last_kmsg[/B]:
adb shell cat /proc/last_kmsg | grep 'mp_decision'[/QUOTE]

[SIZE="4"][B]So, the problem is?[/B][/SIZE]
The problem is that if you're using a Windows OS, Windows OS doesn't have grep installed, so your command would not run and you will see an error message like this:

[IMG]http://i1352.photobucket.com/albums/q647/wcypierre/XDA%20Windows%20Grep%20Workaround/adbgrepwindowserror_zps2961e162.png[/IMG]

Linux or Mac users will not have this problem as they have grep installed, so they are fine.

[SIZE="4"][B]Workaround[/B][/SIZE]: 
1. Install a Linux shell on Windows
2. Use a terminal app within the Android phone 
3. Connect to the linux shell inside the Android Phone by using your computer
4. Use the built-in filters(for logcat ONLY)

[SIZE="4"][B]Workaround #1[/B][/SIZE]
[QUOTE]You can simply click [URL="http://forum.xda-developers.com/showthread.php?t=2072090"]here[/URL] and follow the simple steps to get a linux shell on your computer :)
[/QUOTE]

[SIZE="4"][B]Workaround #2[/B][/SIZE]
[QUOTE]You just need to download a terminal app from your phone and every command will work fine. You would need to omit the adb and adb shell keyword(refer below) in order for the command to work. A nice terminal app suggestion would be [URL="https://play.google.com/store/apps/details?id=jackpal.androidterm&hl=en"]https://play.google.com/store/apps/details?id=jackpal.androidterm&hl=en[/URL] which you can simply download from Google Playstore
[/QUOTE]

[SIZE="4"][B]Workaround #3[/B][/SIZE]
[QUOTE]You can just type "adb shell" and press enter, then type your commands(omit all adb and adb shell keyword) and it will work just as like in workaround #2.
[/QUOTE]

[SIZE="3"][B]Example[/B][/SIZE]
[QUOTE]1. "[B]adb shell[/B]" + enter
2. Choose the command that you wanted:

[B]Logcat[/B]:
logcat | grep 'htc'

[B]Dmesg[/B]:
dmesg | grep 'mp_decision'

[B]last_kmsg[/B]:
cat /proc/last_kmsg | grep 'mp_decision'[/QUOTE]

[SIZE="4"][B]Workaround #4[/B][/SIZE]
[QUOTE]This workaround is a workaround which only exists for logcat, because logcat have a filtering system that is built into it(makes us wonder why it is not built into dmesg and last_kmsg as well eh?). 

For example, the grep command for the logcat above can be replaced by:

[QUOTE]adb logcat htc:V *:S[/QUOTE]

However, the downside is that you need to know the exact name of the app which is logged at the logcat in order to search for it while you can do a random keyword search with grep which helps a lot if you do not know what to look for.

For more information about the filtration, you can refer to [URL="http://developer.android.com/tools/debugging/debugging-log.html"]http://developer.android.com/tools/debugging/debugging-log.html[/URL][/QUOTE]

[SIZE="4"]Conclusion[/SIZE]:
Hopefully, after reading this article, you will know how to deal with grep when you're on Windows OS :)

Do drop me a question or two if you have something that you don't understand and stay tuned for  more articles! :highfive: