Not able to run grep command

Question

I was trying to run the following instruction in Android (Java):

 Process p = Runtime.getRuntime().exec("/system/bin/lsof|grep mediaserver");

but I am getting an error if I run the following instruction:

 Process p = Runtime.getRuntime().exec("/system/bin/lsof ");

the file is successfully saved. Can anyone tell what is the error? Actually I want to list and check if media server service is being running or not.

Well, since you are the one getting the error, perhaps you could tell us what the error is. Maybe then we could help you, no? — verdesmarald, Aug 27 '12 at 14:12
First guess? Since you have to put /system/bin in front of the lsof command, maybe try putting the path to grep in there too? i.e. use /system/bin/lsof | /system/bin/grep mediaserver" or whatever the path to grep is. — billjamesdev, Aug 27 '12 at 14:14
i am getting the following error W/System.err(345): java.io.IOException: Error running exec(). Command: [/system/bin/lsof|grep, init] Working Directory: null Environment: null — chiv, Aug 27 '12 at 14:24

score 1 · Answer 1 · answered Aug 27 '12 at 14:10

1

The grep utility may not be installed on your device.

You can check it by trying the following in a console:

> adb shell
$ grep
grep: not found

The last line indicates that this command is not available.

answered Aug 27 '12 at 14:10

sdabet

18,360
11
89
158

What can I do if grep is missing? Are there shell alternatives? – Elist Jan 28 '16 at 10:05
Check this out: https://stackoverflow.com/questions/27615220/grep-command-not-found-in-adb-shell – sdabet Jan 28 '16 at 10:37

Stephen C · Answer 2 · 2012-08-29T01:39:30.617

The problem is that Runtime.getRuntime().exec(...) does not know how to deal with the shell language. On a Linux / Unix platform you would so something like this:

Process p = Runtime.getRuntime().exec(new String[]{
    "/bin/sh", "-c", "/system/bin/lsof | grep mediaserver"});

However, (apparently) Android doesn't have a command shell / command prompt by default. So either you need to identify and install a suitable shell on your device, or construct the pipeline "by hand"; i.e. by creating a "pipe" file descriptor, and execing the two commands so that lsof writes to the pipe and grep reads from it.

Maybe the answer is to run it like this ...

Process p = Runtime.getRuntime().exec(
        "adb shell /system/bin/lsof | grep mediaserver");

(Try running the "shell ...." part from adb interactively before doing it from Java.)

thanks for the reply i am getting error W/System.err(1370): java.io.IOException: Error running exec(). Command: [/bin/sh, -c, /system/bin/lsof | grep init] Working Directory: null Environment: null — chiv, Aug 27 '12 at 14:58

Not able to run grep command

2 Answers2

Linked