Note: The following answer is over 10 years old. It's probably not the best answer anymore. My current preferred way of accomplishing this is https://stackoverflow.com/a/76551835/1292598

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, to get full logs, you can do:

adb logcat | findstr com.example.package

Logcat logs has got levels at which to get info:

V — Verbose, D — Debug, I — Info, W — Warning, E — Error, F — Fatal, S — Silent

So to get only error logs related to the app, you can update the above command as follows:

adb logcat *:E | findstr com.example.package

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

This works for me with USB debugging:

The solution was to use your device's own logcat directly via shell.

1. Connect the device and use:

   adb shell

2. Use logcat after the shell is set up:

   logcat | grep com.yourapp.packagename

Add filter

Specify names

Choose your filter.

adb logcat -e "package-name" 

This works prefectly when filtering rows for one app only.

For a debuggable application, I suggest

adb shell run-as my.package.name logcat

run-as doesn't work for non-debuggable applications, so for those I use the --uid flag. Unfortunately there isn't a uidof, so I need to extract it from pm. Here's a small sh script to do that:

function logcat {
  pkg="$1"
  shift
  if [ -z "$pkg" ]; then
    >&2 echo 'Usage: logcat pkg ...'
    return 1
  fi

  uid="$(adb shell pm list package -U $pkg | sed 's/.*uid://')"
  if [ -z "$uid" ]; then
    >&2 echo "pkg '$pkg' not found"
    return 1
  fi

  adb logcat --uid="$uid" "$@"
}

Usage is logcat my.package.name. It accepts additional arguments like normal logcat.

I prefer this to the --pidof based solution (see https://stackoverflow.com/a/48004086/1292598) since that requires you to re-run the command each time the process is restarted.

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:

1. Tools -> Android -> Enable ADB Integration.
   If it was already enabled, then toggle it off, and then back on

2. 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...

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.

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

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.

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}') 

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 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"