shell command to find a process id and attach to it?

Question

Hello

I want to attach to a running process using 'ddd', what I manually do is:

# ps -ax | grep PROCESS_NAME

Then I get a list and the pid, then I type:

# ddd PROCESS_NAME THE_PID

Is there is a way to type just one command directly?

Remark: When I type ps -ax | grep PROCESS_NAME, grep will match both the process and grep command line itself.

Answer 1

There is an easy way to get rid of the grep process:

ps -ax | grep PROCESS_NAME | grep -v ' grep '

(as long as the process you're trying to find doesn't include the string " grep ").

So something like this should work in a script (again, assuming there's only one copy running):

pid=$(ps -ax | grep $1 | grep -v ' grep ' | awk '{print $1}')
ddd $1 ${pid}

If you call your script dddproc, you can call it with:

dddproc myprogramname

Although I'd add some sanity checks such as detecting if there's zero or more than one process returned from ps and ensuring the user supplies an argument.

Answer 2

As separate commands:

% PID=`ps -ax | grep ${PROCESS_NAME} | grep -v grep | cut -d ' ' -f 1-2`
% ddd ${PROCESS_NAME} ${PID}

In one line:

% PID=`ps -ax | grep ${PROCESS_NAME} | grep -v grep | cut -d ' ' -f 1-2` && ddd ${PROCESS_NAME} ${PID}

Answer 3

Do this way -

ddd PROCESS_NAME `ps -ax | grep PROCESS_NAME | grep -v grep | awk '{print $1}'`

Answer 4

ddd <process_name> `pgrep <process_name>`

Answer 5

you can use pggrep to find the process

Answer 6

You can use awk to both filter and get the column you want. The "exit" limits the ps results to the first hit.

function ddd_grep() {
  ddd $(ps -ax | awk -v p="$1" '$4 == p { print $1; exit 0; }');
}

ddd_grep PROCESS_NAME

You may have to adjust the columns for your ps output. Also you can change the == to ~ for regex matching.