Develop Reference

Get IMEI via ADB only for old Huawei models

I need a bit of assistance. I have a Huawei g6-l11 (with Android 4.3) from which I am trying to extract the IMEI via ADB. I know that this device is ancient, but this is one of my tasks. So far I had tried everything I could find on the internet, like:
1) adb shell getprop | grep "<IMEI>"
2) adb shell service call iphonesubinfo N | grep "<IMEI>" - Where N is a number between 1 and 50
3) adb shell settings get secure android_id
4) adb shell content query --uri content://settings/secure | grep "<IMEI>"
5) adb shell content query --uri content://settings/system | grep "<IMEI>"
6) adb shell content query --uri content://settings/global | grep "<IMEI>"
7) adb shell dumpsys | grep "<IMEI>"
So I had made an Android app and run this piece of code on the smartphone:
val tm = this.getSystemService(Context.TELEPHONY_SERVICE) as TelephonyManager
Log.d("Emy_","The IMEI is ${tm.deviceId}")
That worked fine but it is an Android app when I need to do the same thing but only via ADB.
Also, I had found a fastboot command that would help me (like: fastboot oem get-psid). But the problem is that I need to reboot the phone into fast boot mode. Which is taking too long.
My questions are:
1) why is it different for Huawei models with the OS version below Marshmallow to extract the IMEI?
2) how could I replicate the function call done by the Java code to be done with the ADB in the terminal? Or in other words, what other commands would you recommend to me to try to extract the IMEI?

You could display it on screen:
adb am start -a android.intent.action.CALL -d tel:*%2306%23

If you just searching to know the IMEI, You can try this code : *#06#
Or you can try this : adb shell
service call iphonesubinfo 1 | toybox cut -d "'" -f2 | toybox grep -Eo '[0-9]' | toybox xargs | toybox sed 's/\ //g'
hop that help you !

adb logcat specific app only [duplicate]

I observed that when i use Logcat with Eclipse with ADT for Android, I get messages from many other applications as well. Is there a way to filter this and show only messages from my own application only.

Linux and OS X
Use ps/grep/cut to grab the PID, then grep for logcat entries with that PID. Here's the command I use:
adb logcat | grep -F "`adb shell ps | grep com.asanayoga.asanarebel | tr -s [:space:] ' ' | cut -d' ' -f2`"
(You could improve the regex further to avoid the theoretical problem of unrelated log lines containing the same number, but it's never been an issue for me)
This also works when matching multiple processes.
Windows
On Windows you can do:
adb logcat | findstr com.example.package

Package names are guaranteed to be unique so you can use the Log function with the tag as your package name and then filter by package name:
NOTE: As of Build Tools 21.0.3 this will no longer work as TAGS are restricted to 23 characters or less.
Log.<log level>("<your package name>", "message");
adb -d logcat <your package name>:<log level> *:S
-d denotes an actual device and -e denotes an emulator. If there's more than 1 emulator running you can use -s emulator-<emulator number> (eg, -s emulator-5558)
Example: adb -d logcat com.example.example:I *:S
Or if you are using System.out.print to send messages to the log you can use adb -d logcat System.out:I *:S to show only calls to System.out.
You can find all the log levels and more info here: https://developer.android.com/studio/command-line/logcat.html
http://developer.android.com/reference/android/util/Log.html
EDIT: Looks like I jumped the gun a little and just realized you were asking about logcat in Eclipse. What I posted above is for using logcat through adb from the command line. I'm not sure if the same filters transfer over into Eclipse.

Since Android 7.0, logcat has --pid filter option, and pidof command is available, replace com.example.app to your package name.
(ubuntu terminal / Since Android 7.0)
adb logcat --pid=`adb shell pidof -s com.example.app`
or
adb logcat --pid=$(adb shell pidof -s com.example.app)
For more info about pidof command:
https://stackoverflow.com/a/15622698/7651532

Add filter
Specify names
Choose your filter.

This works for me with USB debugging:
The solution is to use your device's own logcat directly via shell.
Connect the device and use:
adb shell
Use logcat after the shell is set up:
logcat | grep com.yourapp.packagename

For me this works in mac Terminal
Got to the folder where you have adb then type below command in terminal
./adb logcat MyTAG:V AndroidRuntime:E *:S
Here it will filter all logs of MyTAG and AndroidRuntime

Update May 17
It's been a few years, and thing have changed. And Eclipse is no longer officially supported. So here's two more up-to-date approaches:
1. Android Studio
In the Android monitor toolbox, you can filter logcat per debuggable process. Normally, when you develop an application it is a debuggable process. Every once in a while I am having issues with this, and a do the following:
Tools -> Android -> Enable ADB Integration.
If it was already enabled, then toggle it off, and then back on
Unplug and replug your mobile device.
There are also options to filter via regex and the debug level
2. logcat-color
This is a nice python wrapper on top of adb logcat if you want to use a terminal based solution. The good thing about it is that you can save multiple configurations and simply reuse them. Filtering by tags is quite reliable. You can also filter by package to see logs of one or more apps only, but you start logcat-color right before launching your app.
Old Answer:
It seems that I can't comment to previous answers, so I will post a new one.
This is a comment to Tom Mulcahy's answer, that shows how the command should change so as to work on most devices, since adb shell ps PID column is variable.
NOTE: The command below works for the cases where you have connected many devices. So device id is needed. Otherwise, you can simply omit the brackets '[', ']'
1. To find out the column of pid, type:
adb [-s DEVICE_ID] shell ps | head -n 1
Now memorise the column number for the PID. Numbering starts from 1.
2. Then type the following:
adb [-s DEVICE_ID] logcat | grep $(adb [-s DEVICE_ID] shell ps \
| grep "com.example" | awk -F" " ' {print $PUT_COLUMN_HERE}')
Simply put the column you memorised in PUT_COLUMN_HERE, e.g. $5
Caveat
Each time you re-run your application, you have to re-run the 2nd command, because the application gets a new PID from the OS.

Ubuntu : adb logcat -b all -v color --pid=`adb shell pidof -s com.packagename` With color and continous log of app

This has been working for me in git bash:
$ pid=$(adb shell ps | grep <package name> | cut -c11-15) ; adb logcat | grep $pid

put this to applog.sh
#!/bin/sh
PACKAGE=$1
APPPID=`adb -d shell ps | grep "${PACKAGE}" | cut -c10-15 | sed -e 's/ //g'`
adb -d logcat -v long \
| tr -d '\r' | sed -e '/^\[.*\]/ {N; s/\n/ /}' | grep -v '^$' \
| grep " ${APPPID}:"
then:
applog.sh com.example.my.package

Using Windows command prompt: adb logcat -d | findstr <package>.
*This was first mentioned by jj_, but it took me ages to find it in the comments...

adb logcat -e "appname"
This works prefectly when filtering rows for one app only.

If you are using Android Studio you can select the process from which you want to receive logcats.
Here is the screenshot.

I wrote a shell script for filtering logcat by package name, which I think is more reliable than using
ps | grep com.example.package | cut -c10-15
It uses /proc/$pid/cmdline to find out the actual pid, then do a grep on logcat
https://gist.github.com/kevinxucs/7340e1b1dd2239a2b04a

Use -s !
You should use your own tag, look at:
http://developer.android.com/reference/android/util/Log.html
Like.
Log.d("AlexeysActivity","what you want to log");
And then when you want to read the log use>
adb logcat -s AlexeysActivity
That filters out everything that doesn't use the same tag.
Source

ADT v15 for Eclipse let you specify an application name (which is actually the package value in your androidmanifest.xml).
I love being able to filter by app, but the new logcat has a bug with the autoscroll. When you scroll up a little to look at previous logs, it automatically scrolls back to the bottom in a couple seconds. It seems scrolling 1/2 way up the log does keep it from jumping back to the bottom, but that's often useless.
EDIT: I tried specifying an app filter from the command-line -- but no luck. If someone figures this out OR how to stop the autoscroll, please let me know.

LogCat Application messages
As a variant you can use third party script PID Cat by Jake Wharton. This script has two major advantages:
shows log entries for processes from a specific application package
color logcat
From documentation:
During application development you often want to only display log messages coming from your app. Unfortunately, because the process ID changes every time you deploy to the phone it becomes a challenge to grep for the right thing.
This script solves that problem by filtering by application package.
An output looks like

In order to access the logcats you first need to install ADB command-line tool. ADB command-line tool is a part of android studio platform tools and can be downloaded from here. After this, you need to set the path/environment variable for adb tools. Now you can access logcat from eclipse terminal/ intellij terminal or mac terminal in case you are using a macbook.
adb logcat : To get entire logcat.
adb shell pidof 'com.example.debug' : To get the process id of your app.
adb logcat pid=<pid> : To get logcat specific to your app.
adb logcat pid=<pid>|grep 'sometext' : To filter logcat on basis of some text.
For more info about filtering logcats read this.

On Windows 10, using Ionic, what worked great to me was combine 'findstr' with the "INFO:CONSOLE" generated by all App messages.
So, my command in command line is:
adb logcat | findstr INFO:CONSOLE

I'm not sure there's a way to only see system messages regarding your app, but you can filter based on a string. If you're doing a log within the program, you can just include a certain unique keyword, and filter based on that word.

Try: Window -> Preferences -> Android -> LogCat. Change field "Show logcat view if ..." the value "VERBOSE". It helped me.

If you are using Eclipse, press the green + sign in the logCat window below and put your package name (com.example.yourappname) in the by Application Name box. Also, choose any name comfortable to you in Filter Name box and click ok. You will see only messages related to your application when the filter you just added is chosen from the left pane in the logCat.

Give your log a name. I called mine "wawa".
In Android Studio, go to Android-> Edit Filter Configurations
Then type in the name you gave the logs. In my case, it's called "wawa". Here are some examples of the types of filters you can do. You can filter by System.out, System.err, Logs, or package names:

This is probably the simplest solution.
On top of a solution from Tom Mulcahy, you can further simplify it like below:
alias logcat="adb logcat | grep `adb shell ps | egrep '\bcom.your.package.name\b' | cut -c10-15`"
Usage is easy as normal alias. Just type the command in your shell:
logcat
The alias setup makes it handy. And the regex makes it robust for multi-process apps, assuming you care about the main process only.
Of coz you can set more aliases for each process as you please. Or use hegazy's solution. :)
In addition, if you want to set logging levels, it is
alias logcat-w="adb logcat *:W | grep `adb shell ps | egrep '\bcom.your.package.name\b' | cut -c10-15`"

You can use below command to fetch verbose logs for your application package
adb logcat com.example.myapp:V *:S
Also if you have rolled out your app and you want to fetch error logs from released app, you can use below command.
adb logcat AndroidRuntime:E *:S

I am usually adding something in the log messages to make it distinct. Or for example unity app you can use "Unity" as matching string.
For mac :
adb logcat | grep "MyUniqueString"
for Windows (powershell ):
adb logcat | Select-String "MyUniqueString"

I have different approach, you can try access to local device's shell.
adb shell
and then follow by
logcat | grep com.package.name
This print all containing that package.
Alternatively, You can try flutter logs --verbose

Another way of getting logs of exact package name when you are inside the shell:
logcat --pid $(ps -ef | grep -E "com.example.app\$" | awk '{print $2}')

I tried to use Tom Mulcahy's answer but unfortunately it was not working for applications with multiple processes so I edit it to fit my needs.
#!/bin/bash
if [ "$#" -ne 1 ]; then echo "Illegal number of parameters"; exit 1; fi
echo "Lof for package name: $1"
PROCESSES=`adb shell ps | grep "$1" | cut -c10-15`
NUM_OF_PROCESSES=`echo "$PROCESSES" | wc -l`
if [ $NUM_OF_PROCESSES -eq 0 ]; then echo "The application is not running!"; exit 1; fi
COUNTER=1
for process in $PROCESSES; do
if [ $COUNTER -eq 1 ]; then GREP_TEXT="("; fi
GREP_TEXT+=$process
if [ $COUNTER -eq $NUM_OF_PROCESSES ]; then GREP_TEXT+=")"; else GREP_TEXT+="|"; fi
let COUNTER=COUNTER+1
if [ $COUNTER -gt $NUM_OF_PROCESSES ]; then break; fi
done
adb logcat | grep -E "$GREP_TEXT"

In addition to Tom Mulcahy's answer, if you want to filter by PID on Windows' console, you can create a little batch file like that:
#ECHO OFF
:: find the process id of our app (2nd token)
FOR /F "tokens=1-2" %%A IN ('adb shell ps ^| findstr com.example.my.package') DO SET PID=%%B
:: run logcat and filter the output by PID
adb logcat | findstr %PID%

Running adb commands on all connected devices

Is there a way of running adb commands on all connected devices? To uninstall an app from all connected devices with "adb uninstall com.example.android".
The commands I am interested in is mainly install and uninstall.
I was thinking about writing a bash script for this, but I feel like someone should have done it already :)

Create a bash file and name it e.g. adb+:
#!/bin/bash
adb devices | while read -r line
do
if [ ! "$line" = "" ] && [ "$(echo "$line" | awk '{print $2}')" = "device" ]
then
device=$(echo "$line" | awk '{print $1}')
echo "$device" "$#" ...
adb -s "$device" "$#"
fi
done
Usage: ./adb+ <command>

Building on #Oli's answer, this will also let the command(s) run in parallel, using xargs. Just add this to your .bashrc file:
function adball()
{
adb devices | egrep '\t(device|emulator)' | cut -f 1 | xargs -t -J% -n1 -P5 \
adb -s % "$#"
}
and apply it by opening a new shell terminal, . ~/.bashrc, or source ~/.bashrc.
If you only want to run on devices (or only on emulators), you can change the (device|emulator) grep by removing the one you don't want. This command as written above will run on all attached devices and emulators.
the -J% argument specifies that you want xargs to replace the first occurrence of % in the utility with the value from the left side of the pipe (stdin).
NOTE: this is for BSD (Darwin / Mac OS X) xargs. For GNU/Linux xargs, the option is -I%.
-t will cause xargs to print the command it is about to run immediately before running it.
-n1 means xargs should only use at most 1 argument in each invocation of the command (as opposed to some utilities which can take multiple arguments, like rm for example).
-P5 allows up to 5 parallel processes to run simultaneously. If you want instead to run the commands sequentially, simply remove the entire -P5 argument. This also allows you to have two variations of the command (adball and adbseq, for example) -- one that runs in parallel, the other sequentially.
To prove that it is parallel, you can run a shell command that includes a sleep in it, for example:
$ adball shell "getprop ro.serialno ; date ; sleep 1 ; date ; getprop ro.serialno"
You can use this to run any adb command you want (yes, even adball logcat will work! but it might look a little strange because both logs will be streaming to your console in parallel, so you won't be able to distinguish which device a given log line is coming from).
The benefit of this approach over #dtmilano's & approach is that xargs will continue to block the shell as long as at least one of the parallel processes is still running: that means you can break out of both commands by simply using ^C, just like you're used to doing. With dtmilano's approach, if you were to run adb+ logcat, then both logcat processes would be backgrounded, and so you would have to manually kill the logcat process yourself using ps and kill or pkill. Using xargs makes it look and feel just like a regular blocking command line, and if you only have one device, then it will work exactly like adb.

This is an improved version of the script from 強大な. The original version was not matching some devices.
DEVICES=`adb devices | grep -v devices | grep device | cut -f 1`
for device in $DEVICES; do
echo "$device $# ..."
adb -s $device $#
done

To add in the ~/.bashrc or ~/.zshrc:
alias adb-all="adb devices | awk 'NR>1{print \$1}' | parallel -rkj0 --tagstring 'on {}: ' adb -s {}"
Examples:
$ adb-all shell date
$ adb-all shell getprop net.hostname
$ adb-all sideload /path/to/rom.zip
$ adb-all install /path/filename.apk
$ adb-all push /usr/local/bin/frida-server-arm64 /data/local/tmp/frida-server
Explanation: awk extracts the device id/host (first column: print $1) of every lines except the first one (NR>1) to remove the "List of devices attached" header line), then gnu parallel runs adb -s <HOSTNAME> <whatever-is-passed-to-the-alias> on whatever non-empty line (-r) in the order specified (-k, to avoid random order / fastest response order) and prepend each line with on <DEVICE>:\t for clarity, all in parallel (-j0, possible to set another number to define how many adb should be ran in parallel instead of unlimited).
:)

This is the highest result on Google, so for all Windows users coming here let me add this solution by User zingh (slightly modified to accept arbitrary commands, rather than "only" install
Batch file (adball.bat):
FOR /F "skip=1" %%x IN ('adb devices') DO start adb -s %%x %*
Call as:
adball uninstall com.mypackage
(%* takes all input parameters, my line above makes it so that all commands are passed to adb as they are, so that you can type multiple words, flags etc.)
Note: you can even use this directly from the Android Studio "run all" popup, if you install the Powershell-plugin. You can add adball to your path, then double-tap ctrl and run
powershell adball uninstall com.mypackage

adb wrapper supports selecting multiple targets for adb commands and parallel execution.
From its README:
# Installation
./install.sh ~/apps/android-sdk-linux
# Execute adb commands on all connected devices.
adb set-target all
# Execute adb commands on given devices.
adb set-target emulator-5554 C59KGT14263422
# Use GNU parallel for parallel install.
adb set-parallel true
(Disclaimer: I have written half of it)

How to use ADB Shell when Multiple Devices are connected? Fails with "error: more than one device and emulator"

$ adb --help
-s SERIAL use device with given serial (overrides $ANDROID_SERIAL)
$ adb devices
List of devices attached
emulator-5554 device
7f1c864e device
$ adb shell -s 7f1c864e
error: more than one device and emulator

Use the -s option BEFORE the command to specify the device, for example:
adb -s 7f1c864e shell
For multiple Emulator, use the process's IP and port as the id, like:
adb -s 192.168.232.2:5555 <command>
See How to get the Android Emulator's IP address?
But if there is only a single Emulator, try:
adb -e <command>
See also http://developer.android.com/tools/help/adb.html#directingcommands

adb -d shell (or adb -e shell).
This command will help you in most of the cases, if you are too lazy to type the full ID.
From http://developer.android.com/tools/help/adb.html#commandsummary:
-d - Direct an adb command to the only attached USB device. Returns an error when more than one USB device is attached.
-e - Direct an adb command to the only running emulator. Returns an error when more than one emulator is running.

Another alternative would be to set environment variable ANDROID_SERIAL to the relevant serial, here assuming you are using Windows:
set ANDROID_SERIAL=7f1c864e
echo %ANDROID_SERIAL%
"7f1c864e"
Then you can use adb.exe shell without any issues.

To install an apk on one of your emulators:
First get the list of devices:
-> adb devices
List of devices attached
25sdfsfb3801745eg device
emulator-0954 device
Then install the apk on your emulator with the -s flag:
-> adb -s "25sdfsfb3801745eg" install "C:\Users\joel.joel\Downloads\release.apk"
Performing Streamed Install
Success
Ps.: the order here matters, so -s <id> has to come before install command, otherwise it won't work.
Hope this helps someone!

I found this question after seeing the 'more than one device' error, with 2 offline phones showing:
C:\Program Files (x86)\Android\android-sdk\android-tools>adb devices
List of devices attached
SH436WM01785 offline
SH436WM01785 offline
SH436WM01785 sideload
If you only have one device connected, run the following commands to get rid of the offline connections:
adb kill-server
adb devices

The best way to run shell on any particular device is to use:
adb -s << emulator UDID >> shell
For Example:
adb -s emulator-5554 shell

As per https://developer.android.com/studio/command-line/adb#directingcommands
What worked for my testing:
UBUNTU BASH TERMINAL:
$ adb devices
List of devices attached
646269f0 device
8a928c2 device
$ export ANDROID_SERIAL=646269f0
$ echo $ANDROID_SERIAL
646269f0
$ adb reboot bootloader
WINDOWS COMMAND PROMPT:
$ adb devices
List of devices attached
646269f0 device
8a928c2 device
$ set ANDROID_SERIAL=646269f0
$ echo $ANDROID_SERIAL$
646269f0
$ adb reboot bootloader
This enables you to use normal commands and scripts as if there was only the ANDROID_SERIAL device attached.
Alternatively, you can mention the device serial every time.
$ adb -s 646269f0 shell

This gist will do most of the work for you showing a menu when there are multiple devices connected:
$ adb $(android-select-device) shell
1) 02783201431feeee device 3) emulator-5554
2) 3832380FA5F30000 device 4) emulator-5556
Select the device to use, <Q> to quit:
To avoid typing you can just create an alias that included the device selection as explained here.

User #janot has already mentioned this above, but this took me some time to filter the best solution.
There are two Broad use cases:
1) 2 hardware are connected, first is emulator and other is a Device.
Solution : adb -e shell....whatever-command for emulator and adb -d shell....whatever-command for device.
2) n number of devices are connected (all emulators or Phones/Tablets) via USB/ADB-WiFi:
Solution:
Step1) run adb devices THis will give you list of devices currently connected (via USB or ADBoverWiFI)
Step2) now run adb -s <device-id/IP-address> shell....whatever-command
no matter how many devices you have.
Example to clear app data on a device connected on wifi ADB I would execute:
adb -s 172.16.34.89:5555 shell pm clear com.package-id
to clear app data connected on my usb connected device I would execute:
adb -s 5210d21be2a5643d shell pm clear com.package-id

For Windows, here's a quick 1 liner example of how to install a file..on multiple devices
FOR /F "skip=1" %x IN ('adb devices') DO start adb -s %x install -r myandroidapp.apk
If you plan on including this in a batch file, replace %x with %%x, as below
FOR /F "skip=1" %%x IN ('adb devices') DO start adb -s %%x install -r myandroidapp.apk

Create a Bash (tools.sh) to select a serial from devices (or emulator):
clear;
echo "====================================================================================================";
echo " ADB DEVICES";
echo "====================================================================================================";
echo "";
adb_devices=( $(adb devices | grep -v devices | grep device | cut -f 1)#$(adb devices | grep -v devices | grep device | cut -f 2) );
if [ $((${#adb_devices[#]})) -eq "1" ] && [ "${adb_devices[0]}" == "#" ]
then
echo "No device found";
echo "";
echo "====================================================================================================";
device=""
// Call Main Menu function fxMenu;
else
read -p "$(
f=0
for dev in "${adb_devices[#]}"; do
nm="$(echo ${dev} | cut -f1 -d#)";
tp="$(echo ${dev} | cut -f2 -d#)";
echo " $((++f)). ${nm} [${tp}]";
done
echo "";
echo " 0. Quit"
echo "";
echo "====================================================================================================";
echo "";
echo ' Please select a device: '
)" selection
error="You think it's over just because I am dead. It's not over. The games have just begun.";
// Call Validation Numbers fxValidationNumberMenu ${#adb_devices[#]} ${selection} "${error}"
case "${selection}" in
0)
// Call Main Menu function fxMenu;
*)
device="$(echo ${adb_devices[$((selection-1))]} | cut -f1 -d#)";
// Call Main Menu function fxMenu;
esac
fi
Then in another option can use adb -s (global option -s use device with given serial number that overrides $ANDROID_SERIAL):
adb -s ${device} <command>
I tested this code on MacOS terminal, but I think it can be used on windows across Git Bash Terminal.
Also remember configure environmental variables and Android SDK paths on .bash_profile file:
export ANDROID_HOME="/usr/local/opt/android-sdk/"
export PATH="$ANDROID_HOME/platform-tools:$PATH"
export PATH="$ANDROID_HOME/tools:$PATH"

Running adb commands on all connected devices
Create a bash (adb+)
adb devices | while read line
do
if [ ! "$line" = "" ] && [ `echo $line | awk '{print $2}'` = "device" ]
then
device=`echo $line | awk '{print $1}'`
echo "$device $# ..."
adb -s $device $#
fi
done
use it with
adb+ //+ command

you can use this to connect your specific device :
* adb devices
--------------
List of devices attached
9f91cc67 offline
emulator-5558 device
example i want to connect to the first device "9f91cc67"
* adb -s 9f91cc67 tcpip 8080
---------------------------
restarting in TCP mode port: 8080
then
* adb -s 9f91cc67 connect 192.168.1.44:8080
----------------------------------------
connected to 192.168.1.44:8080
maybe this help someone

Here's a shell script I made for myself:
#! /bin/sh
for device in `adb devices | awk '{print $1}'`; do
if [ ! "$device" = "" ] && [ ! "$device" = "List" ]
then
echo " "
echo "adb -s $device $#"
echo "------------------------------------------------------"
adb -s $device $#
fi
done

For the sake of convenience, one can create run configurations, which set the ANDROID_SERIAL:
Where the adb_wifi.bat may look alike (only positional argument %1% and "$1" may differ):
adb tcpip 5555
adb connect %1%:5555
The advance is, that adb will pick up the current ANDROID_SERIAL.
In shell script also ANDROID_SERIAL=xyz adb shell should work.
This statement is not necessarily wrong:
-s SERIAL use device with given serial (overrides $ANDROID_SERIAL)
But one can as well just change the ANDROID_SERIAL right before running the adb command.
One can even set eg. ANDROID_SERIAL=192.168.2.60:5555 to define the destination IP for adb.
This also permits to run adb shell, with the command being passed as "script parameters".

How to run logcat on multiple devices?

How can I run logcat on multiple devices at the same time? "adb logcat" command gives an error:
error: more than one device and emulator

Use the -s option of adb:
adb -s <serialnumber>
Example
C:\Users\lel>adb devices
List of devices attached
192.168.198.101:5555 device
0123456789ABCDEF device
adb -s 0123456789ABCDEF logcat
adb -s 192.168.198.101:5555 logcat
You can combine grep whit this, to get all lines that contain it.
an example is with System.out
Example:
adb -s 192.168.198.101:5555 logcat | grep "System.out"

I thought it might be useful. I have this script that helps me a lot. It logcats each device to a different file. To stop logging just press CTRL+C.
#! /bin/bash
devices=`adb devices | grep 'device$' | cut -f1`
pids=""
for device in $devices
do
log_file="$device-`date +%d-%m-%H:%M:%S`.log"
echo "Logging device $device to \"$log_file\""
adb -s $device logcat -v threadtime > $log_file &
pids="$pids $!"
done
echo "Children PIDs: $pids"
killemall()
{
echo "Killing children (what a shame...)"
for pid in $pids
do
echo "Killing $pid"
kill -TERM $pid
done
}
trap killemall INT
wait

Use your device ip:
adb -s device_ip:5555