file test operations in android

Hello all,

I am not able to do file test operations in android

if I am executing below command

-b /dev/ttyACM0

it is saying

*-b: not found*

if I am executing in script

device0="/dev/ttyACM0" # / (root directory) if [ -b "$device0" ]

it is giving

*:] not found * I tried test -b /dev/ttyACM0 that is also giving error test not found

Can anybody tell me how to execute file test operations in android*

*Thanks & Regards

O S L Reddy*

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