diff options
Diffstat (limited to 'zsh/functions')
| -rw-r--r-- | zsh/functions/anonsh | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/zsh/functions/anonsh b/zsh/functions/anonsh new file mode 100644 index 0000000..c9b1b4f --- /dev/null +++ b/zsh/functions/anonsh @@ -0,0 +1,72 @@ +# Convenience helper to set up an "incognito mode" for a shell session. +# +# Installation: +# 1. Create a folder like ~/.zsh/functions +# 2. Add it to your ZSH function path with fpath=(~/.zsh/functions(:A) $fpath) in ~/.zshenv +# 3. Save this script as ~/.zsh/functions/anonsh +# 4. Add `autoload -Uz anonsh` to your ~/.zshrc +# +# Now you can type `anonsh` in any zsh session +# +# - Use `clear` to clear both the screen and scrollback buffer +# - Use `fc -p` to clear command history without affecting your usual HISTFILE + +# Only store new command history entries in RAM +unset HISTFILE + +# Redefine the hardstatus text to "anonsh" so it doesn't show $PWD +# where people can see it when the shell doesn't have focus +# +# (The zsh_hardstatus_pre* and title functions are part of my .zshrc setup) +if typeset -f zsh_hardstatus_precmd > /dev/null && typeset -f title > /dev/null; then + autoload -Uz add-zsh-hook + add-zsh-hook -d precmd zsh_hardstatus_precmd + add-zsh-hook -d preexec zsh_hardstatus_preexec + + function zsh_hardstatus_precmd { title "anonsh" "anonsh"; } + add-zsh-hook precmd zsh_hardstatus_precmd + add-zsh-hook preexec zsh_hardstatus_precmd +fi + +# Show ... in the prompt instead of $PWD so it can't give away +# something after running `clear` +# +# ($base_prompt is a custom part of my .zshrc setup) +if (( ${+base_prompt} )); then + export base_prompt="${base_prompt//%%1~/...}" +fi +export PS1="${PS1//%%1~/...}" +export PS2="${PS2//%%1~/...}" +export PS3="${PS3//%%1~/...}" +export PS4="${PS4//%%1~/...}" + +# Redefine "clear" to also clear the GNU screen scrollback buffer and to ask +# for the terminal scrollback buffer to be cleared in as many ways as possible +clear() { + # Call the regular clear command + command clear + + # Manually emit all the escapes I know for requesting the terminal be + # cleared and ask GNU Screen to pass it through as a literal + # + # Source: https://apple.stackexchange.com/a/318217/388700 + printf '\eP\e[2J\e[3J\e[;H\ec\e\\' + + # Flush GNU Screen's internal scrollback for this shell + if [ "$TERM" = "screen" ]; then + screen -X scrollback 0 + screen -X scrollback 5000 + fi +} + +# TODO: Try to find a workaround to call the terminal scrollback-clearing part +# of `clear` on switching GNU screen focus and then refresh the visible +# part from screen's stored copy so nothing anonsh can show accidentally. +# +# (Without removing the `termcapinfo` line to from ~/.screenrc which +# would disable it when `anonsh` isn't in use.) + +# Call `clear` on exit to clear terminal scrollback +zshexit() { clear; } + +# vim: set ft=zsh : |