Get process status by pid in Ruby

Question

Is there a way to get a process's child process status based on its PID in Ruby? For example, in Python you can do psutil.Process(pid).status

Accepted Answer

I don't know of a portable ruby method to get process state of a running process. You can do `Process.wait` and check `$?.exitstatus`, but that doesn't look like what you want. For a posix solution, you could use

```
`ps -o state -p #{pid}`.chomp
```

to get the letter code ps produces for process state

```
PROCESS STATE CODES
Here are the different values that the s, stat and state output specifiers
(header "STAT" or "S") will display to describe the state of a process.
D    Uninterruptible sleep (usually IO)
R    Running or runnable (on run queue)
S    Interruptible sleep (waiting for an event to complete)
T    Stopped, either by a job control signal or because it is being traced.
W    paging (not valid since the 2.6.xx kernel)
X    dead (should never be seen)
Z    Defunct ("zombie") process, terminated but not reaped by its parent.
```

Get process status by pid in Ruby

Solution

Problem