Question

I’m testing mobile Android devices and I would like to redirect the device log on a file whose name indicates both the date and time of my test, and the device model that is being tested.
For the first issue, I have already resolved with

now=$(date +"%b_%d_%Y_%k_%M");adb logcat -c;adb logcat|tee $now

So:

$ echo $now
Jan_03_2012_13_09

and the tee command creates a file with this filename.

As for the device model I have written two bash lines that obtain it from adb shell, namely

device=$(adb shell cat /system/build.prop | grep "^ro.product.device=")
deviceshortname=$(echo $device | sed 's/ro.product.device=//g')

(not optimal as I am not very good in bash programming… 🙂 but I manage to get

$ echo $deviceshortname
LT15i

My problem is how to combine $now and $deviceshortname to obtain a filename such as:
LT15i_Jan_03_2012_13_19

I tried to set another variable:

filename=($(echo $deviceshortname"_"$now))

and got:

$ echo $filename
LT15i_Jan_03_2012_13_19

but if I try redirecting the log:
$ adb logcat | tee $filename

I obtain such file:

-rw-r--r--+ 1 ele None     293 Jan  3 13:21 ?[01;31m?[K?[m?[KLT15i_Jan_03_2012_13_19

I don’t know why these strange characters and what I’m doing wrong.

Answer 1

Something is adding color to your output. It might be grep(1), it might adb, it might be baked into the /system/build.prop resource that you’re reading.

If you’re lucky, it is being added by grep(1) — because that is supremely easy to disable with --color=no:

device=$(adb shell cat /system/build.prop | grep --color=no "^ro.product.device=")
deviceshortname=$(echo $device | sed 's/ro.product.device=//g')

If the colors are being added by adb, then perhaps it has a command line option that asks it to avoid colorizing the output.

If the colors are hard-coded into the /sys/build.prop resource in some way, then you’ll need some little tool that filters out the color codes. I don’t have one handy (and it’s bedtime) but you can probably build one starting with tr(1) to delete \033 ASCII ESC characters.