For some reason, tmux is not available as a yum package on CentOS 6.x:

[root@SysopUtility src]# cat /etc/redhat-release 
CentOS release 6.3 (Final)
[root@SysopUtility ~]# yum install tmux
No package tmux available.

which means a manual install is called for. First install Libevent, but do not install the yum package because it does not provide the correct files. Download and install the source instead:

  1. go to and download the latest stable.
    [root@SysopUtility src]# wget 
  2. [root@SysopUtility src]#  configure && make && make install

Now install tmux source:

[root@SysopUtility src]# wget
[root@SysopUtility src]# configure; make; make install
if the above fails, you may need to run configure like this:
./configure CFLAGS="-I/usr/local/include" LDFLAGS="-L/usr/local/lib"
Now if you run tmux and it complains about
tmux: error while loading shared libraries: cannot open shared object file: No such file or directory
then do the following:
[root@SysopUtility tmux-1.8]# cat - >> /etc/profile.d/
# Initialization script for bash and sh
# necessary for tmux
export LD_LIBRARY_PATH="/usr/local/lib"
<Ctrl-d for EOF>
[root@SysopUtility tmux-1.8]# source /etc/profile.d/ 
Now you should have a working tmux.

To save the entire screen buffer to a file, get into the edit mode and run:

capture-pane -S -32768
save-buffer /tmp/buffer_file