Search code examples
androidshellgrepadbcut

adb | grep | cut not showing result... but cat | grep | cut is ok

Having some issue on using adb, grep and cut. I have a command below

adb logcat | grep MYTEXT

this has result of several text that has ":" separating them.

If I use the below to remove text before ":", it doesn't work.

adb logcat | grep MYTEXT | cut -d':' -f 2-

However if I first dump into a file and then do the same. It works.

adb logcat > mylog.out
cat mylog.out | grep MYTEST | cut -d':' -f 2-

I can use this approach as workaround, but I would prefer not to need to dump to mylog.out first as temporary step in my script.

Anyone to enlighten? Thanks!

Solution

  • Assuming no typos (MYTEXT/MYTEST) or other similar issues are involved here then this is likely related to buffering of data and volume of data.

    Telling grep to buffer its output by lines with the --line-buffered option will probably help here.

    adb logcat | grep --line-buffered MYTEXT | cut -d':' -f 2-

    As might using the unbuffer or stdbuf utilities.