I am looking for a command that allow me to copy the entire output of a tmux session from bash. For example:
$ tmux ls
0: 1 windows (created Wed Mar 2 20:19:19 2022) [213x54]
I would like to copy all output in this session to a file from my bash session. Something like:
sh copy-tmux.sh [tmux-session-id]
Related
The naive way to do this is not working. Try this:
Start a first tmux session.
$ export ENVIRONMENT="production"
$ tmux
You can then verify that inside the session ENVIRONMENT is production
Then, in a second terminal start another session
$ export ENVIRONMENT="staging"
$ tmux
Surprisingly in this session ENVIRONMENT is also production! This is very unintuitive!
What is going on here?
How can I achive this? I like all windows in a session to "inherit" the ENVIRONMENT variable.
The "simplest" solution is to create a new tmux server with the different environment.
$ ENVIRONMENT=production tmux -L prod-tmux
and
$ ENVIRONMENT=staging tmux -L staging-tmux
You'll always need to specify which socket, prod-tmux or staging-tmux, to use whenever you reconnect to an existing session.
The next solution would be to use one server, but modify the environment of each session in that server. Something like
$ tmux new-session -d -s production
$ tmux new-session -d -s staging
$ tmux set-environment -t production ENVIRONMENT production
$ tmux set-environment -t staging ENVIRONMENT staging
Note that ENVIRONMENT would not be set in the process running in the initial window for each session, but will be for any subsequent window created. (Unless the server inherited ENVIRONMENT when it first started.)
When you run tmux, it first looks for an existing server (either the default server, or the one specified by either the -L or -S options). If there is no server, one is started, and the server's environment is inherited from the current environment.
If there is a server, tmux simply requests the server to execute a tmux command (by default, new-session, or whatever command is specified by an argument to tmux) command, then exits. The environment of the tmux command itself isn't relevant, unless the requested command is documented to read from it (cf. set-environment).
The server manages a group of windows, each of which represents a process created by the server (not the tmux command itself). A session is just a logical group of windows, also managed by the server.
Newer versions of tmux seem to support this natively! I do devops support for multiple clients and wanted to set a separate bash history file for each client. The following works very well for me! It sets the working directory, to the client/project dir, and sets the bash history file path
tmux new -c ~/Documents/code/CLIENT/ -e HISTFILE=~/Documents/code/CLIENT/.bash_history -s CLIENT -d
Based on the excellent answer by #chepner we can solve this issue by adding aliases to define different tmux commands for different servers. For example we could append the following to ~/.bashrc.
# somewhere in ~/.bashrc
alias tmux-s1='tmux -L s1'
alias tmux-s2='tmux -L s2'
alias tmux-s3='tmux -L s3'
alias tmux-s4='tmux -L s4'
alias tmux-s5='tmux -L s5'
Now we can use tmux-s1, tmux-s2, etc... the same way we would normally use the tmux command except each variant will be associated with a different server. When we create a session for a server that has no active sessions then the current environment variables will be used to initialize the server. To reattach to the session we will need the alias for the server that the session was created with.
Example
$ export ENVIRONMENT="production"
$ tmux-s1 ls
no server running on /tmp/tmux-12345/s1
$ tmux-s1
############### now attached to session 0 on server s1 ################
$ echo $ENVIRONMENT
production
################### (ctrl+b,d) detach from session ####################
[detached (from session 0)]
$ tmux-s1 ls
0: 1 windows (created Sun Nov 17 18:13:18 2019) [80x20]
$ export ENVIRONMENT="staging"
$ tmux-s2 ls
no server running on /tmp/tmux-12345/s2
$ tmux-s2
############### now attached to session 0 on server s2 ################
$ echo $ENVIRONMENT
staging
################### (ctrl+b,d) detach from session ####################
[detached (from session 0)]
$ tmux-s2 ls
0: 1 windows (created Sun Nov 17 18:13:22 2019) [80x20]
I created a new session of tmux, intending to use the -s flag to name it, but confused the command with -S which specifies a socket. I know the session is alive, because the processes I started in it are still running. But when I try to list running sessions it does not appear. Where is my session and how do I recover it?
In tmux option -S means socket path (from man tmux):
-S socket-path
Specify a full alternative path to the server socket. If -S is specified, the default
socket directory is not used and any -L flag is ignored.
So you have to find out the parent directory where tmux was run with
-S option and pass this option to tmux to point it to the
alternative socket path. You could for example find PID of the
tmux process:
$ ps aux | grep '[t]mux'
ja 15121 0.0 0.0 20252 2236 pts/6 S+ 00:44 0:00 tmux -S new
And then check this process cwd in /proc like this:
$ ls -l /proc/15121/cwd
lrwxrwxrwx 1 ja users 0 Aug 19 00:52 /proc/15121/cwd -> /home/ja
And then to refer to this tmux session:
$ tmux -S /home/ja/new ls
0: 1 windows (created Sat Aug 19 00:44:46 2017) [212x65] (attached)
File ~/.tmux.conf
new-session -n terminal
Run tmux by command:
tmux
Result: two sessions found in sessions lists (check by ctrl+b s)
(0) + 1: 1 windows (attached)
(1) + terminal: 1 windows
I would like to have only terminal session which I've defined in my config file.
(0) + 1: 1 windows (attached) - first session that created by the tmux command.
Then tmux load configs and create one more session (1) + terminal: 1 windows because you have new-session -n terminal line in .tmux.conf
To create one session remove new-session -n terminal from .tmux.conf and start tmux as tmux or tmux new -s session_name
So I've created a script which omits creation additional session (only those defined in configuration)
#!/bin/sh
tmux -2 attach-session -d
I know that I can run tmux -V to find the version of tmux that is in my PATH, but how can I get the version of tmux that is currently running?
As pointed out in a comment, tmux -V returns the version:
$ tmux -V
tmux 3.0a
Tested on Centos 7 and OSX 12.5.
Most obvious, but not 100% correct way is to execute this command in console
$ tmux -V
and receive output like this tmux 2.9a with version of tmux INSTALLED, not currently running.
In 99% cases it is enough, but there can be subtle nuances.
Command tmux -V will return version of tmux installed at /usr/bin/tmux or any other directory inside your PATH variable. If you have tmux already running, it is possible that tmux can be started from binary of other version and from different place (for example, tmux can be started from /home/user/bin/tmux).
In this case, you have to call
$ ps -e | grep tmux
to see PID of all tmux processes currently running. It will output something like this
[vodolaz095#ivory ~]$ ps -e | grep tmux
19699 pts/0 00:00:00 tmux: client
19701 ? 00:00:00 tmux: server
Here, number 19701 depicts process id (PID) of currently running tmux server.
After getting PID of tmux server, you can ran command
$ lsof -p 19701
to get information about CURRENTLY RUNNING tmux server process (in my case its 19701) that will output something like this (Figure 1)
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
tmux:\x20 19701 vodolaz095 cwd DIR 8,33 4096 22544385 /home/vodolaz095
tmux:\x20 19701 vodolaz095 rtd DIR 8,1 4096 2 /
tmux:\x20 19701 vodolaz095 txt REG 8,1 677760 3675332 /usr/bin/tmux
tmux:\x20 19701 vodolaz095 mem REG 8,1 6406312 131327 /var/lib/sss/mc/group
as you can see, tmux currently running was executed from binary placed in /usr/bin/tmux.
Or, you can call one liner
lsof -p `pgrep 'tmux: server'`
to achieve the same output as Figure 1
After you get path to tmux binary CURRENTLY RUNNING, (in my case, it was /usr/bin/tmux), you can execute this binary with flag -V to get its version
/usr/bin/tmux -V
or, if tmux was installed by limited user into /home/user/bin/tmux,
/home/user/bin/tmux -V
And, as result, you'll get version of tmux currently running, not the one, that was installed.
To get the version of the tmux server you can use display-message.
./tmux2.3 display-message -p "#{version}"
Will show the version of the server (2.7 in my case)
-p will direct the output of stdout so you can script with it and {version} can be anything from the FORMATS section in the man page.
The following will give you the executable of your tmux server, on linux:
realpath /proc/$(tmux display-message -p "#{pid}")/exe
And on macos, proc_pidpath can be used, see https://stackoverflow.com/a/8149380
To find the actual version of the tmux that is running, you have to find the PID of the tmux:
pgrep tmux
With this info, you can check the version by running:
lsof -p $tmuxPID | grep REG | grep -i -e deleted -e "tmux$"
If there is not a (deleted) next to the tmux file listed, you can just run that file with a -V.
If it results in files that are "(deleted)", you are running an old, uninstalled version. If you are on linux, you can figure out what it is by running:
/proc/$tmuxPID/exe -V`
If you are on OS X, you are stuck with whatever information is in the path to the filename, possibly something like Cellar/tmux/<version number>/bin/tmux.
You can combine many of these steps into the following one-liner:
for tmuxPID in $(pgrep tmux); do lsof -p $tmuxPID | grep REG | grep -i -e deleted -e "tmux$"; done
Or if you are on Linux, this always works:
for tmuxPID in $(pgrep tmux); do /proc/$tmuxPID/exe -V; done
Is there any way to re-number or swap tmux sessions, just as you can renumber or swap tmux windows? I can't see any command for it and want to easily switch between certain sessions.
They're sorted by name (which defaults to a number) You can change the names so that they appear in the order that you prefer.
Outside of tmux:
tmux rename-session -t 0 zzz
inside tmux:
C-b $
Or:
c-b : rename session -t current_name new_name
The default ordering seems to have changed recently from name to index. If you want to put it back to name, try this in your .tmux.conf
bind s choose-tree -sZ -O name
If you'd like to "manually" order your sessions, you can prefix the session name with a zero-width or invisible unicode character. For example:
$ tmux rename-session -t charlie $(echo -e "\u200B")charlie
$ tmux rename-session -t beta $(echo -e "\u200C")beta
$ tmux rename-session -t alpha $(echo -e "\u200D")alpha
$ tmux list-sessions
charlie: 1 windows (created Sun Nov 2 12:39:30 2014) [284x87] (attached)
beta: 1 windows (created Sun Nov 2 12:39:27 2014) [284x87]
alpha: 1 windows (created Sun Nov 2 12:39:23 2014) [284x87]
The drawback is that you still have to refer to the session using those characters.