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If I have multiple copies of the same application on the disk, and only one is running, as I can see with ps, how can I know the absolute path to distinguish it from the others?

Peter Mortensen
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Jader Dias
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8 Answers8

176
% sudo ls -l /proc/PID/exe

eg:

% ps -auxwe | grep 24466
root     24466  0.0  0.0   1476   280 ?        S     2009   0:00 supervise sshd
% sudo ls -l /proc/24466/exe
lrwxrwxrwx 1 root root 0 Feb  1 18:05 /proc/24466/exe -> /package/admin/daemontools-0.76/command/supervise
Breakthrough
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akira
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    In my system (ubuntu 14.04) you do not have to be superuser to run the `ls` command. – jarno Mar 05 '16 at 08:42
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    @jarno `ls: cannot read symbolic link /proc/28783/exe: Permission denied` -- it's not about running the `ls` command, it's about accessing the process info of a process not belonging to you. On my box, about 97% of all processes listed in /proc are root processes, and the others are distributed over 11 different users. – Irfy Mar 21 '16 at 12:53
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    ls: cannot read symbolic link '/proc/87/exe': No such file or directory lrwxrwxrwx 1 root root 0 Oct 9 07:05 /proc/87/exe – CS QGB Oct 08 '22 at 23:06
33

Use:

pwdx $pid

This gives you the current working directory of the pid, not its absolute path.

Usually the which command will tell you which is being invoked from the shell:

#> which vlc
/usr/bin/vlc
Peter Mortensen
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seenu
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    @Kokizzu No, it doesn't because it doesn't answer the question at all. The which command only tells you which binary will be run if you execute the command now. The question was "which binary is already running there". Imagine for example having a dozen jdks on your computer. If you want to know for a running java process which jdk it's been taken from, which doesn't help you with that. It will only tell you which jdk it will be taken from, if you execute it now. The accepted answer is also the correct one. – noamik Feb 18 '16 at 09:05
  • An obvious way this answer is wrong: on my machine I run processes with different JDK versions and some 32bits/64bits. If I want to identify the correct jstack/jmap version for the process the answer above will not work while the accepted answer will. – Daniel Da Cunha Dec 07 '16 at 07:36
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    @Kokizzu This only answers the question, "What is the current working directory of the process `$pid`?" The edited post still doesn't answer the question. `which` merely tells "If the command is on the path, then what is it?" – John Strood Jun 05 '18 at 11:42
  • `pwdx` return me the absolute path of the exectuable program of the process depending on pid on redhat x64 6.3. – Nick Dong Dec 30 '18 at 06:05
  • This does not answer the question at all. – Peter Mortensen Dec 30 '20 at 14:53
19

One way is ps -ef

fpmurphy
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ps auxwwwe

Source:

https://serverfault.com/questions/62322/getting-full-path-of-executables-in-ps-auxwww-output

Community
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Jader Dias
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    does not show ALL full qualified paths on my linux: "root 24466 0.0 0.0 1476 280 ? S 2009 0:00 supervise sshd " for example – akira Feb 01 '10 at 17:04
  • This is more accurate than the other answers... maybe not as useful, but more the right answer. Upvoted. – John Hunt Aug 30 '17 at 14:55
  • Can you add sample output and how to interpret it (for a self-contained answer)? Display of all environment variables makes for a lot of noise. E.g., is it the "_" variable that contains the answer? – Peter Mortensen Nov 20 '20 at 05:27
6

lsof is an option. You can try something like below:

lsof -p PROCESS_ID

This will list all the files opened by the process including the executable's actual location. It is then possible to add a few more awk, cut, grep etc. to find out the information that you are looking for.

As an example, I executed the following commands to identify where my 'java' process came from:

lsof -p 12345 | awk '{print $NF}' | grep 'java$'
Pablo A
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ram
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The quick answer is to use ps with options or the /proc filesystem info. That will usually work, but is not guaranteed. In general, there is no definite, guaranteed answer. For instance, what if the executing file is deleted during execution, so that there is no path to the file?

See the Unix FAQ for a little more detail, particularly questions 4.3 and 4.4.

mpez0
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0

You could use 

readlink /proc/$(pgrep -x -U $(id -ur) APP_NAME)/exe

or 

find /proc/$(pgrep -x -U $(id -ur) APP_NAME)/exe -printf "%l\n"

to get the absolute path of APP_NAME running as current user.

jarno
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0

UPDATED due to David Moles' comment, below.

See other answers for the path to the executable.

In case you need it, this will give you the working directory of the process. You don't need to know the PID:

pwdx `pgrep ###process_name###`
moodboom
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