Pane Title in Tmux - command-line

Question

On my local machine I've got 3 node.js instances running simultaneously. Each has it's own pane in a tmux window called "servers". The problem is that it's not that easy to figure out which node is running in which pane, 'cause their logs are similar.
What I need is a title for every pane. As I got, tmux itself doesn't have the feature: it has only titles for windows and not for panes. Launching a separate tmux session inside every pane for every node.js instance looks like an overkill.
So is there some small program that launches a command, wrapping its output with a specified status bar?

Answer 1

This functionality has been added to tmux in this commit. It is not in version 2.2, but it looks like it will be in 2.3.
To enable it:
tmux set -g pane-border-status top
or if you prefer:
tmux set -g pane-border-status bottom
To set a custom text as your pane border status line you can make use of pane-border-format, e.g. like so:
tmux set -g pane-border-format "#{pane_index} #{pane_current_command}"

Answer 2

tmux does support per-pane titles, but it does not provide a per-pane location to display these titles.
You can set a pane’s title with the escape sequence ESC ]2; … ESC \ (e.g. see the section called Names and Titles in the tmux manpage). You could do this from the shell like this:
printf '\033]2;%s\033\\' 'title goes here'
Each pane’s title defaults to the system’s hostname. By default the active pane’s title is displayed on the right side of the tmux status line (the default global value of the session variable status-right is "#22T" %H:%M %d-%b-%y, which shows 22 characters of the pane’s title, the time, and the date).
So, as long as you are satisfied with being able to see the active pane’s title (i.e. willing to switch panes to see the title of an inactive pane), you can get by with the default functionality. Just send the appropriate title-setting escape sequence before starting the main command for each pane.
If you absolutely need a dedicated line to display some per-pane information, then nested tmux sessions may not be as much (unnecessary) “overkill” as you might first think.
In the general case, to provide an inviolate status line on some given terminal, you will need a full terminal (re)emulator that sits between the original terminal and a new terminal (one with one fewer lines). Such (re)emulation is needed to translate control sequences sent to the inner terminal and translate them for the original terminal. For example, to maintain a status line at the bottom of the outer terminal, the command
Move to the last line.
sent to the inner terminal must be become
Move to the next to last line.
when translated for and sent to the outer terminal. Likewise, an LF sent to the inner terminal must become
If the cursor is on the next to last line, then scroll this line and all the lines above it up one line, to provide a clear next-to-last line (protecting the status line on the last line).
Otherwise, send an LF.
in the outer terminal.
Programs like tmux and screen are just such terminal re-emulators. Sure, there is a lot of other functionality wrapped around the terminal emulator, but you would need a large chunk of terminal emulation code just to provide a reliable status line.
There is, however, a light-weight solution as long as
your programs (Node.js instances) have limited terminal interactions with the panes in which they are running (i.e. no cursor positioning), and
you do not resize the panes while your programs are running.
Like many terminal emulators, tmux supports a “set scrolling region” terminal control command in its panes. You could use this command to limit the scrolling region to the top (or bottom) N-1 lines of the terminal and write some sort of instance-identifying text into the non-scrolling line.
The restrictions (no cursor movement commands allowed, no resizing) are required because the program that is generating the output (e.g. a Node.js instance) has no idea that scrolling has been limited to a particular region. If the output-generating program happened to move the cursor outside of the scrolling region, then the output might become garbled. Likewise, the terminal emulator probably automatically resets the scrolling region when the terminal is resized (so the “non-scrolling line” will probably end up scrolling away).
I wrote a script that uses tput to generate the appropriate control sequences, write into the non-scrolling line, and run a program after moving the cursor into the scrolling region:
#!/bin/sh
# usage: no_scroll_line top|bottom 'non-scrolling line content' command to run with args
#
# Set up a non-scrolling line at the top (or the bottom) of the
# terminal, write the given text into it, then (in the scrolling
# region) run the given command with its arguments. When the
# command has finished, pause with a prompt and reset the
# scrolling region.
get_size() {
set -- $(stty size)
LINES=$1
COLUMNS=$2
}
set_nonscrolling_line() {
get_size
case "$1" in
t|to|top)
non_scroll_line=0
first_scrolling_line=1
scroll_region="1 $(($LINES - 1))"
;;
b|bo|bot|bott|botto|bottom)
first_scrolling_line=0
scroll_region="0 $(($LINES - 2))"
non_scroll_line="$(($LINES - 1))"
;;
*)
echo 'error: first argument must be "top" or "bottom"'
exit 1
;;
esac
clear
tput csr $scroll_region
tput cup "$non_scroll_line" 0
printf %s "$2"
tput cup "$first_scrolling_line" 0
}
reset_scrolling() {
get_size
clear
tput csr 0 $(($LINES - 1))
}
# Set up the scrolling region and write into the non-scrolling line
set_nonscrolling_line "$1" "$2"
shift 2
# Run something that writes into the scolling region
"$#"
ec=$?
# Reset the scrolling region
printf %s 'Press ENTER to reset scrolling (will clear screen)'
read a_line
reset_scrolling
exit "$ec"
You might use it like this:
tmux split-window '/path/to/no_scroll_line bottom "Node instance foo" node foo.js'
tmux split-window '/path/to/no_scroll_line bottom "Node instance bar" node bar.js'
tmux split-window '/path/to/no_scroll_line bottom "Node instance quux" node quux.js'
The script should also work outside of tmux as long as the terminal supports and publishes its csr and cup terminfo capabilities.

Answer 3

Since tmux 2.6 you can do:
$ tmux select-pane -t {pane} -T {title}
# Examples:
$ tmux select-pane -T title1 # Change title of current pane
$ tmux select-pane -t 1 -T title2 # Change title of pane 1 in current window
$ tmux select-pane -t 2.1 -T title3 # Change title of pane 1 in window 2
You can see title per pane in a status bar with:
$ tmux set pane-border-status bottom # For current window
$ tmux set -g pane-border-status bottom # For all windows
Disable status bar with:
$ tmux set pane-border-status off # For current window
$ tmux set -g pane-border-status off # For all windows

Answer 4

I am using tmux version 2.3, I think border style is not supported in previous versions.
this is what worked for me:
For each pane set the title:
printf '\033]2;My Pane Title\033\\'
Then:
tmux set -g pane-border-format "#{pane_index} #T"

Answer 5

A gif is worth a thousand words. (source)
tmux-xpanes is a tmux-based terminal divider, which supports
displaying title for each pane through the newly added -t option.

Answer 6

I'm working on the pane status bar for tmux - ticket.
My development branch can be found here on github:
https://github.com/jonathanslenders/tmux
Right now, this already adds a working rename-pane "title" command. There are still some bugs, and the API will improve. The idea is to create a status bar per pane, which can have some formatting, like the session status bar. Like the rest of tmux, everything should become scriptable, and customizable. When finished and stable, it will probably be included in the official tmux.

Answer 7

Yes there is such a command: tmux. Give your session a name and it will be displayed in an inner status bar:
TMUX=0 tmux new-session -s my-new-session

Answer 8

TL;DR
Append following configs to your tmux config file (in my case is ~/.tmux.conf.local)
# dispaly pane_current_path as the pane title
set -g pane-border-status top
set -g pane-border-format "#{pane_index} #{pane_current_path}"
then run:
tmux source-file ~/.tmux.con
enjoy it
Thanks to https://stackoverflow.com/a/37602055/5121972

Answer 9

This is not helpful in the short-term, but there is a feature request for per-pane titles in tmux: http://sourceforge.net/tracker/?func=detail&aid=3495916&group_id=200378&atid=973265#
In the meantime, as others mentioned, nesting tmux works decently.

Answer 10

Adding these three lines inside .tmux.conf worked and doesn't intervene with the pane_title variable managed by tmux
set -g pane-border-status top
set -g pane-border-format "#[fg=black, bg=green] #{pane_index} #{#custom_pane_title}"
bind < command-prompt -p "New Title: " -I "#{#custom_pane_title}" "set-option -p #custom_pane_title '%%'"
After adding these lines, source the .tmux.conf to reflect the changes
tmux source-file ~/.tmux.conf
Inside tmux pane, press Ctrl+B <, enter the title of your choice, and pane title will be set.
The rationale to use a different variable
Pane title can be set from multiple sources, and I wanted to avoid any interference with it.
tmux select-pane -T title1
using escape sequence characters `printf '\033]2;%s\033\' 'title goes here
ref: https://gist.github.com/ethagnawl/db27bba3c4cccdc30ade2a0c54f49723

Answer 11

All existing answers don't mention how to actually change the default title, but the solution is hidden over at https://unix.stackexchange.com/a/564690/28354, and, for example, on Android Termux tmux, you can change the default title of "localhost" to the model name instead, like so, from within a zsh shell:
tmux set-hook -g after-split-window "select-pane -T \"$(getprop ro.product.model)\""
tmux set-hook -g after-new-window "select-pane -T \"$(getprop ro.product.model)\""
tmux set-hook -g after-new-session "select-pane -T \"$(getprop ro.product.model)\""
This will change the "localhost" from bottom-right status bar next to the clock, because pane_title is what's used, which, in turn, defaults to the hostname:
% tmux show-options -g status-right
status-right "#{?window_bigger,[#{window_offset_x}#,#{window_offset_y}] ,}\"#{=21:pane_title}\" %H:%M %d-%b-%y"
[0] 0:zsh 1:zsh 2:zsh- 3:zsh* "Pixel 2 XL" 22:55 26-Sep-21
Additionally, it can be made to be displayed at the top of each pane, too:
tmux set -g pane-border-status top
The format is controlled by pane-border-format, and it defaults as follows:
% tmux show-options -g pane-border-format
pane-border-format "#{?pane_active,#[reverse],}#{pane_index}#[default] \"#{pane_title}\""