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Asked: 2021-04-17 08:38:04 +0800 CST

how to use grep and sed on adb logcat

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I'm currently using grep in combination with adb logcat (android console api). Now I want to edit every line on the fly using sed in a pipe. However when using sed after grep the output becomes empty. Does anyone know why? Also: adb logcat keeps on running with grep which might be part of the issue, however I don't know how to fix it

here is an example

$ adb logcat | grep "Average inference"

gives me

04-16 13:51:19.528  8065  8065 E tflite  : Average inference timings in us: Warmup: 38350.1, Init: 2158247, Inference: 70339.2Overall max resident set size = 65.7773 MB, total malloc-ed size = 0 MB, in-use allocated/mmapped size = 10.3201 MB  
04-16 13:51:19.528  8065  8065 E tflite  : Average inference timings in us: Warmup: 38350.1, Init: 2158247, Inference: 70339.2Overall max resident set size = 65.7773 MB, total malloc-ed size = 0 MB, in-use allocated/mmapped size = 10.3201 MB

Now I want to use this pipe to extract all numbers (after "Warmup")

sed -e 's/^.*Warmup//' -e 's/[^0-9.0-9]/ /g'

to get the following result

38350.1 2158247 70339.2 65.7773 0 10.3201
38350.1 2158247 70339.2 65.7773 0 10.3201

however

adb logcat | grep "Average inference" | sed -e 's/^.*Warmup//' -e 's/[^0-9.0-9]/ /g'

only gives me an empty output

Update:

In general adb logcat gives me many arbitrary outputs which I would need to suppress. So a typical ouput would look like

05-04 20:18:00.063  5670  6838 I LiveIconUtil: mIconDpi : 480 , mTargetIconDpi : 240
05-04 20:18:00.081  5670  6838 I AppIconSolution: load= live icon for com.sec.android.app.clockpackage, from overlay = false
05-04 20:18:00.082  5670  6838 I LauncherActivityInfo: Load live icon for com.sec.android.app.clockpackage
05-04 20:18:00.082  5670  6838 I LauncherActivityInfo: packageName: com.sec.android.app.clockpackage, useThemeIcon: false, height: 144, width: 144, density: 480
05-04 20:18:00.103  5670  5670 E libprocessgroup: set_timerslack_ns write failed: Operation not permitted
05-04 20:18:00.138  5270  5270 W GraphicUtils: getTextEmpty : skipped with null text
05-04 20:18:00.138  5270  5270 W GraphicUtils: setLinearGradientTextColor : skipped with null text
05-04 20:18:03.232  4462  4462 I SurfaceFlinger: SFWD update time=991188773612812
04-16 13:51:19.528  8065  8065 E tflite  : Average inference timings in us: Warmup: 38350.1, Init: 2158247, Inference: 70339.2Overall max resident set size = 65.7773 MB, total malloc-ed size = 0 MB, in-use allocated/mmapped size = 10.3201 MB  
04-16 13:51:19.528  8065  8065 E tflite  : Average inference timings in us: Warmup: 38350.1, Init: 2158247, Inference: 70339.2Overall max resident set size = 65.7773 MB, total malloc-ed size = 0 MB, in-use allocated/mmapped size = 10.3201 MB  
...

So I would still somehow need to grep the "Average inference" lines, only with using sed instead as suggested by @FritjofLarsson

bash

1 Answers

  1. Best Answer

    This should do (no need for grep):

    #!/bin/sh

adb logcat | sed -n '
/Average inference/ {
    s/.*Warmup: //
    s/[^0-9]\{2,\}/ /g
    # Optional: remove the trailing space.
    s/ $//
    p
}
'

    /Average inference/ will only match lines containing 'Average inference'.
    s/.*Warmup: // makes sed discard anything before the first occurrence of 'Warmup: '.
    s/[^0-9]\{2,\}/ /g will replace every two or more consecutive non-digit characters with a space. The decimal point will be preserved since it is surrounded by digits.
    s/ $// will trim the trailing space introduced by s/[^0-9]\{2,\}/ /g when ' MB' was replaced in the end of the line.
    p is used in combination with -n flag in order to make sed only output the modified lines.

    Note: You may write the sed command in one line like this:
    sed -n '/Average inference/{s/.*Warmup: //;s/[^0-9]\{2,\}/ /g;s/ $//;p}'

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