Sometime ago I made a simple script for my zsh setup that allows me to see whether am I in a cabalized sandbox environment or not. I posted it to Haskell-cafe a month ago, but totally forgot to post it to this blog.
The result of checking for the sandbox is cached, which is probably unnecessary; it updates only when the user performs a cabal command or changes a directory.
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| # | |
| # This simple script displays whether you are in a cabal sandbox | |
| # the the result of checking for a sandbox is cached, but now that I | |
| # actually think about it, it was probably an unnecessary step. | |
| # Don't forget to customize the PROMPT variable at the bottom | |
| # | |
| # Looks like this with my prompt: https://files.app.net/rjphjAG9.png | |
| # | |
| function update_cabal_sandbox_info () { | |
| if [[ -a cabal.sandbox.config ]] | |
| then | |
| export __CABAL_SANDBOX=" sandboxed" | |
| else | |
| export __CABAL_SANDBOX= | |
| fi | |
| export __CABAL_SANDBOX_VARS_INVALID= | |
| } | |
| function get_cabal_sandbox_info () { | |
| test -n "$__CABAL_SANDBOX_VARS_INVALID" && update_cabal_sandbox_info | |
| echo $__CABAL_SANDBOX | |
| } | |
| typeset -ga preexec_functions | |
| typeset -ga precmd_functions | |
| typeset -ga chpwd_functions | |
| setopt prompt_subst | |
| export __CABAL_SANDBOX= | |
| export __CABAL_SANDBOX_VARS_INVALID=1 | |
| chpwd_functions+='update_cabal_sandbox_chpwd' | |
| update_cabal_sandbox_chpwd () { | |
| export __CABAL_SANDBOX_VARS_INVALID=1 | |
| } | |
| preexec_functions+='update_cabal_sandbox_preexec' | |
| update_cabal_sandbox_preexec () { | |
| case "$(history $HISTCMD)" in | |
| *cabal*) export __CABAL_SANDBOX_VARS_INVALID=1 ;; | |
| esac | |
| } | |
| SLR_DARKSEA=%{$fg_bold[green]%} | |
| sandbox_prompt () { | |
| test -n $__CABAL_SANDBOX && echo "$SLR_DARKSEA$(get_cabal_sandbox_info)${reset_color}" | |
| } | |
| PROMPT="$(sandbox_prompt) , %~ \n" |
After you place the contents of the script in your .zshrc file (or in a similar location), you should update your $PROMPT to use $(sandbox_prompt). The prompt I am using, by the way, is
HOST_COLOR=%{$fg_bold[yellow]%}
local ret_status="%(?:%{$fg_bold[green]%}:%{$fg_bold[red]%})%?%{$reset_color%}"
PROMPT=$'\n$(ssh_connection)$HOST_COLOR%n@%m%{$reset_color%}$(my_git_prompt)$(sandbox_prompt) : %~\n[${ret_status}] %# 'and it is based on the oh-my-solarized theme.
(parentheses) 