Filter processes in Go

I have a Go script that takes user input from the config file and executes a command like this ps -ef | grep <USER_INPUT>. The purpose of this script is to collect application monitoring information from the java processes. In order to collect this information, the user needs to tell the go script from which processes they want to collect this information.

In the current implementation, if I pass input java as user input then the script is executing ps -ef | grep java command and returning all processes where the word java matches. Next, the script is collecting monitoring information from all these processes.

Now I want to enhance the logic to achieve the below scenario:

• Find processes with the given username
• Find processes where a particular word matches
• Ignore processes where a particular word matches

Let's say I have the following 4 processes running on my server:

user1  2683  1  0 Dec03 ?        00:06:28 java -Xms2g -Xmx48g -DlogDir=. -DuploadDir=. -jar webapp-runner-8.0.33.4.jar -AconnectionTimeout=3600000 --port 8080 app1.war
user2 26568  1  1 06:32 pts/3    00:00:32 java -Xms2g -Xmx12g -DlogDir=. -DuploadDir=. -jar webapp-runner-9.0.31.0.jar -AconnectionTimeout=3600000 --port 9010 app2.war
user3 89568  1  1 06:32 pts/3    00:00:28 java -Xms2g -Xmx12g -DlogDir=. -DuploadDir=. -jar webapp-runner-9.0.31.0.jar -AconnectionTimeout=3600000 --port 9020 app3.war
user2 12657  1 22 Nov21 ?        1-05:51:45 java -Xmx1g -jar entrypoint.jar MS_ENV=dev MS_NAME=dev-cron MS_ID= MS_CLASS=com.test.cron.Cron

Now say from the above processes, I want to collect monitoring information from the processes that are owned by a user user2 and user3, from the processes where the word java matches, and ignore processes where word cron matches.

The output should be:

user2 26568  1  1 06:32 pts/3    00:00:32 java -Xms2g -Xmx12g -DlogDir=. -DuploadDir=. -jar webapp-runner-9.0.31.0.jar -AconnectionTimeout=3600000 --port 9010 app2.war
user3 89568  1  1 06:32 pts/3    00:00:28 java -Xms2g -Xmx12g -DlogDir=. -DuploadDir=. -jar webapp-runner-9.0.31.0.jar -AconnectionTimeout=3600000 --port 9020 app3.war

Is it possible to pass regex or any other command as user input to achieve this? Can someone please help me out with this?

Passing user input to a command line tool is a big security no-no of the user is not trused. You are better of by calling ps -ef (statically not with user input), and then applying a regex yourself using the regexp library.

Alternatively, if you are writing a Go program anyway, you might consider getting the data you need directly from /proc, or use a library like go-ps. This saves you having to parse output that is meant for humans and directly get computer readable data. (However this depends on you usecase)