How to find which Tmux session a process belongs to?

Question

I've got JS to run with a php upload form.

Everytime I go to upload a file to test this the file DOES upload but the progress bar doesn't work and I get an 'Upload Aborted' error message.

Below is the JS

function _(el) {
            return document.getElementById(el);
        }
        function uploadfile() {
            var file = _("file").files[0];
            var formdata = new FormData();
            formdata.append("file", file);
            var ajax = new XMLHttpRequest();
            ajax.upload.addEventListener("progress", progressHandler, false);
            ajax.addEventListener("load", completeHandler, false);
            ajax.addEventListener("error", errorHandler, false);
            ajax.addEventListener("abort", abortHander, false);
            ajax.open("POST", "uploader.php");
            ajax.send(formdata);
        }
        function progressHandler(event) {
            var percent = (event.loaded / event.total) * 100;
            _("progressbar").value = (percent);
        }
        function completeHandler(event) {
            _("status").innerHTML = "Upload Success";
            _("progressbar").value = 0;
        }
        function errorHandler(event) {
            _("status").innerHTML = "Upload Failed";
        }
        function abortHander(event) {
            _("status").innerHTML = "Upload Aborted";
        }

This script attachs to an HMTL5 <progress> with a default value of 0 and max of 100.

Here is the php file to which I am linking the form to:

<?php 
$email = $_POST['email'];
$name = $_POST['name'];
$spc = '[email protected]';
$message = $_POST['message'];
$size = $_FILES['file']['size'];
$file = $_FILES['file']['tmp_name'];
$filename = $_FILES['file']['name'];
$filetype = $_FILES['file']['type'];
$link = 'http://www.spcink.com/uploads/' . $email . '%7c' . $name;
if(!empty($file)) {
    mkdir('../uploads/' . $email . '|' . $name, 0777, true);
    move_uploaded_file($file, '../uploads/' . '/'. $email . '|' . $name . '/' . $filename);
    mail($spc, 'File upload from:' . $name, $message . $link);
}
?>

I can't seem to figure out what is wrong here. Could some one please look this over and help me out! Thank you!

Solution 1

lsof /path/to/.file.swp will show the process ID of the offending vim process. If you want to write a script, use pid=$(lsof -Fp "$swp_file"); pid=${pid#p} to get just the process ID.

Then ps 12345 where 12345 is the process ID will show some information about the process, in particular what tty it's running on (ps -o tty= -p $pid in a script). The tty uniquely identifies a tmux window (assuming the process is running inside tmux), but I don't know how to go from the tty name to the tmux session.

What would give you the tmux session is the value of the TMUX environment variable in the vim process. The session number is the last number, after the last comma.

Most unices have a way to find out the environment of a process, but the way differs between unix variants. On Linux, you can use </proc/$pid/environ grep -z '^TMUX=' to show the value of $TMUX in process $pid, so you can extract the session number as $(</proc/$pid/environ grep -z '^TMUX=' | sed 's/.*,//').

Solution 2

This shell snippet works pretty well for me (you'll need the pstree utility as well):

for s in `tmux list-sessions -F '#{session_name}'` ; do
  echo -e "\ntmux session name: $s\n--------------------"
  for p in `tmux list-panes -s -F '#{pane_pid}' -t "$s"` ; do
    pstree -p -a -A $p
  done
done

For two tmux sessions with two vim's each, I get this output:

tmux session name: 0
--------------------
zsh,3444
  `-vim,3467 file_1
zsh,3474
  `-vim,3495 file_2

tmux session name: 1
--------------------
zsh,3526
  `-vim,3547 file_3
zsh,3554
  `-vim,3576 file_4

Solution 3

Iterating using the response from Tor, a small bash snippet to get the session, window and pane where a particular PID is running:

export PID=1161102; for s in `tmux list-sessions -F '#{session_name}'` ; do
  for p in `tmux list-panes -s -F '#{pane_pid}' -t "$s"` ; do
    pstree -h -p -a -A $p | grep "[,]$PID" && tmux list-panes -s -t "$s" -f "#{==:#{pane_pid},$p}" -F '#{session_name}: #{window_index}.#{pane_index}'
  done
done

Example output:

  `-skydive,1161102 analyzer -c skydive.yml
SESSIONNAME: 2.3

Comments

[lkraav]

yes indeed, this basically works, at least for scenario when original vi process isn't sudoed. /proc/$pid/environ was new to me, good thinking on that. getting the session value as a number is good enough since the session id letters >9 simply increase alphabetically.

[lkraav]

when using sudo to launch the hypothetical vi process to find session by, it looks like it needs to have sudo -E for the TMUX variable to travel into it's environ.

[Gilles 'SO- stop being evil']

@lkraav: Best: use sudoedit instead of sudo vim. Also useful to know for other cases: either use sudo -E or put Defaults !env_reset in /etc/sudoers. In a pinch: find out the parent process of vim, which is likely to be a shell running in the same tmux window, and get its TMUX variable.

[akavel]

great, thanks! also, adding -h in pstree call will highlight the current pane, FWIW; or, passing -P $PID instead should highlight some $PID you might be searching. But you don't really need this, I suppose.

[lucidbrot]

Accessing /proc/pid/environ did not work for me using sudo, but with cat it works