Getting to know the PID of the running process is useful. The PID could be used by OS utilities to find out the information about the process itself. It is also valuable to know the PID in case of process failure, so you can trace the process behavior across the system in system logs, such as /var/log/messages, /var/log/syslog.

This recipe shows you how to use the os package to obtain a PID of the executed program, and use it with the operating system utility to obtain some more information.

1. Open the console and create the folder chapter01/recipe06.
2. Navigate to the directory.
3. Create the main.go file with the following content:

        package main

        import (
          "fmt"
          "os"
          "os/exec"
          "strconv"
        )

        func main() {
 
          pid := os.Getpid()
          fmt.Printf("Process PID: %d \n", pid)

          prc := exec.Command("ps", "-p", strconv.Itoa(pid), "-v")
          out, err := prc.Output()
          if err != nil {
            panic(err)
          }

          fmt.Println(string(out))
        }

4. Run the code by executing the go run main.go.

5. See the output in the Terminal:

The function Getpid from the os package returns the PID of a process. The sample code shows how to get more information on the process from the operating system utility ps.

It could be useful to print the PID at the start of the application, so at the time of the crash, the cause could also be investigated by the retrieved PID.