How I can run a command in Tmux when I'm attaching to a session ?
I want attach and immediately run a command.
I read the docs, but found only send keys, which not suits my needs.
6 Answers
You can attach to a running tmux session and spawn a new window which runs a particular command:
tmux attach \; new-window vim
Note that this does not spawn vim in the pre-exsiting window - there is no facility for doing that, it doesn't really make sense: as @Falcon Momot points out, an existing window could be running anything, the only way to issue commands is "send keys".
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4Great answer! This must be obvious to most readers, but it took me a while to realize it, so just in case anyone else has the same question: the
\;is an escaped semicolon, used here to separate twotmuxcommands (without escaping the semicolonnew-windowswould be treated as a new shell command).– JoeOct 14, 2014 at 10:49
I was searching for a solution to this exact problem. It can be done using 'set-buffer' and 'paste-buffer' commands
tmux att -t <session-name> \; set-buffer "<command>^M" \; paste-buffer
Here is a complete example :
# let's start with two sessions running bash
tmux new -s theOtherSession \; detach
tmux new -s astropanic \; rename-window main-window \; detach
# attach to the 'astropanic' session, run a directory listing, output
# current datetime, then detach. Note for carriage return (^M) type ^V^M
tmux att -t astropanic \; find-window main-window \; set-buffer "ls;date^M" \; paste-buffer \; detach
# reconnect to check status
tmux att -t astropanic
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1I did not manage to do
carriage returnas you said. I had to send the enter key like this:tmux attach -t "$1" \; set-buffer "ls;date" \; paste-buffer \; send-keys C-m. Oct 19, 2017 at 22:53 -
1This should be the accepted answer. Basically you should name a window and make the name stick by adding
DISABLE_AUTO_TITLE="true"to your shell profile (this is important), then use this window only to run commands upon connecting. I use it to connect to a ssh host and then get my kerberos ticket at the start of the day.ssh hostname -t "tmux a -t 0 \; select-window -t cmd \; set-buffer \"kinit -f -l 1d -r 30d^M\" \; paste-buffer \;". For convenience, give it a nice name and save it as a script in your path. :) Also note the ^M should be inserted by pressing C-v then Enter in your editor.– GauravAug 17, 2018 at 17:23
It's not clear to me what kind of command you want to run, a tmux command or a shell/OS command. Here's an example of each:
#!/bin/bash
cd
# give the session a name; makes it easier to reuse code lines
_SNAME=Generic
# start a whole new tmux session
tmux new-session -s $_SNAME -d -x 140 -y 35
# can set tmux options
tmux set-option -t $_SNAME default-path /opt/foo/build
# create a new window that's just a shell
tmux new-window -t $_SNAME -n build -d
# create a new window that's running a program
tmux new-window -t $_SNAME -n vim -d vim
This leaves the session unattached. If you want to attach to it, too, add this line at the end of the shell script:
# attach to the new session
tmux attach -t $_SNAME
Try out this to run mutt, for example
tmux has-session -t mail
if [ $? != 0 ]
then
tmux new-session -s mail -n mel_GMAIL -d "TERM=xterm-256color ; mutt -F $HOME/.mutt/muttrc_perso"
fi
lxterminal --command="tmux attach -t mail"
It checks the existence of a 'mail' session running, if not, it creates one and starts the application mutt; finally it attaches to it
Here is a little script that starts or attach to Tmux and runs a command in it. Once the command has been executed, it'll exit Tmux.
#!/bin/sh -x
SESSION_NAME=foo
tmux has-session -t $SESSION_NAME 2>/dev/null
if [ $? -ne 0 ]
then
tmux new-session -d -s $SESSION_NAME "$*"
fi
exec tmux attach -t $SESSION_NAME
Usage example:
$ ./script-above 'echo hello world && sleep 10'
I like to do this:
#!/bin/bash
function tmuxed {
/usr/local/bin/tmux new-session -d -s bkp 2&>/dev/null
/usr/local/bin/tmux send-keys "/Users/xxx/bin/thisscript backup" C-m
}
function backup {
echo 'bla bla doing stuff'
}
$1
And run /Users/xxx/bin/thisscript tmuxed
vi.