Tag Archives: bash

Using screen for lazy dot files

I have a lot of shell accounts; on my laptops and workstations, on my ARM build boxes, on remote servers, and so on. I don’t make a lot of customisations to my login shell as the lowest common¬†denominator¬†of OS X, FreeBSD and various Linux distros has trained me to live with what is on the host.

I do have two exceptions, bash and screen1. Handling my screen config is easy; just scp my .screenrc file to the new host. Handling the small number of changes to my bash setup is more involved as bash has several places it looks in (.bashrc, .bash_profile, sometimes just .profile) and those files may already exist on the host.

Recently I’ve been experimenting with the idea of using screen to handle this customisation, which reduces the amount of configuration data copied to a new host to a single new file. Here is a sample .screenrc from an ARM FreeBSD build box.

startup_message off
vbell off

# Window list at the bottom.
hardstatus alwayslastline "%{wk}%-w%{Gk}[%n %t]%{wk}%+w%=%{Ck}%M%d %c%{-} %{=r} ${USER}@%H"

# who needs .bashrc ?
shell bash
setenv PS1 "\[\e]0;\u@\h: \w\a\]\h(\w) % "
setenv GOROOT /u/go                           
# yup, screen can expand shell vars
setenv PATH $PATH:$GOROOT/bin:$GOPATH/bin 

autodetach on
term xterm-color
termcapinfo xterm ti@:te@

Combined with ssh $HOST -t -- screen -R -D, this makes setting up a new machine very simple.

1. Note to haters. I know that alternatives like zsh and tmux exist, but neither are installed by default on any mainstream distro, so until they are, I don’t care. At any rate, these suggestions probably apply equally well to your chosen shell and screen multiplexer.

Bash trick ‘o the day

Bash supports the += operator

% echo $PATH
% PATH+=:$HOME/bin
% echo $PATH