Overview
So if you’ve used GNU Screen and liked it, I think you’ll love tmux. It’s basically GNU screen on steriods.
It all started when I wanted to split a terminal window into two sub-terminal windows, similar to how vim can split the terminal window to display multiple buffers.
Now that widescreen monitors are a thing (yes, I just dated myself), the best way to divide a screen is vertically. Unfortunately, GNU screen doesn’t support this with the release that comes with most distros unless you patch it. Furthermore, screen just looks kinda disgusting when it does a split.
Some googling quickly pointed me to tmux, which is pretty gosh-durned awesome.
I’ve only scratched the surface of its features, but I had some trouble getting my ~/.tmux.conf all set up the way I wanted, so I thought I’d write it up.
I found the following writeup from HawkHost super helpful as well:
Escape Key
GNU screen defaults its escape key to CTRL-a, and tmux defaults to CTRL-b. I personally prefer the backtick or ` key, because it gets away from command sequences I use a lot that involve the CTRL key.
However, the backtick key shows up a lot in scripting, so we’ll need to be able to switch back and forth between backtick and CTRL-b.
We can use the escape key plus F11 and F12 to switch back and forth with the following ~/.tmux.conf lines:
# command prefix (like screen) unbind C-b set-option -g prefix ` bind-key F11 set-option -g prefix C-b bind-key F12 set-option -g prefix `
So to switch to CTRL-b, you’d hit the following:
` F11
To switch back, you’d use
CTRL-b F12
Status Bar
One of tmux’s cool features is you can add a status bar to the bottom. I’ve chosen to display user@hostname on the left, and the load averages then date/time on the right.
# Set status bar set -g status-bg black set -g status-fg white set -g status-interval 30 set -g status-left-length 30 set -g status-left '#(whoami)@#(hostname -s)' set -g status-right '#(cut -d " " -f 1-3 /proc/loadavg) %y-%m-%d %H:%M'set-window-option -g window-status-current-bg white set-window-option -g window-status-current-fg black setw -g automatic-rename
| This line must be set -g status-right #(uptime | cut -d ': -f4) %y-%m-%d %H:%M' in OSX. |
Panes
Pane Coloring
If your version of tmux supports it, you can make your pane dividers look nice:
# Set pane divider set -g pane-border-bg black set -g pane-border-fg white set -g pane-active-border-bg black set -g pane-active-border-fg white
Pane Hotkeys
So, using the " key to make new panes is really annoying because it defaults to horizontal. In order to fix that, we can remap the pipe (|) and dash (-) keys to split the window vertically and horizontally if you want.
# Set pane hotkeys unbind % bind-key | split-window -h bind-key - split-window -v
Navigating Panes
The fastest way to navigate between panes is using the q hotkey. Doing so displays a number on each pane. Pressing the appropriate number on the keyboard will send you to the appropiate pane.
This is much better than navigating using the o hotkey for the next pane.
link-panes
So tmux includes a link-window command, which is like a symlink for windows. Every time you make a change to a window, it’s reflected on the linked window. This holds true for windows in different sessions.
Unfortunately, as of 11-07-27, there is no link-pane command:
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http://www.mail-archive.com/tmux-users@lists.sourceforge.net/msg00634.html
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http://ideas.jwcxz.com/ See "Improvements for Tmux"
To work around this, we can use GNU screen!
In the source pane, run a new instance of screen. Then, in the pane you want to link to the source pane, run screen -x, which will open the screen session.
Credit goes to Saugata Ghose for asking about this feature in tmux, and for the following Unix adventure to figure out the workaround.