Get PID from TID I run `iotop` to check on programs that are heavy disk users, in case I need to decrease their priority. Usually this is good enough, but `iotop` only shows thread ID (TID), and sometimes I want to know process ID (PID) so I can find out more about which process is responsible. Unfortunately, while `ps` can display TID (a.k.a SPID, LWP), it doesn't have a flag to take a list of TIDs the way it does for a list of PIDs with `--pid`. The best I can do is list TIDs and then `grep` the output. For example, if the thread id is 792, I can do $ ps -eLf | grep ' 792 ' which works reasonably well, but is a little inelegant. Is there a better way?

You can always do:


ps -eLo pid= -o tid= | awk '$2 == 792 {print $1}'


On Linux:


$ readlink -f /proc/*/task/792/../..
/proc/300


Or with `zsh`:


$ echo /proc/*/task/792(:h:h:t)
300