Better command line history in zsh with peco

Some years ago I bumped into peco, a Simplistic interactive filtering tool written in Go; at that time there was a bit of hype around this kind of command line tools, with several implementations published on Github. I settled on peco because it was fast enough, compared for example to the Python implementation, to be tolerable in my daily shell usage.

A nice and often overlooked feature of bash and zsh (provided by readline) is reverse-i-search, which allows you to search and reuse previous commands from your shell history; unfortunately the presentation of this command is quite basic and kinda hard to navigate, and this is where peco brings value.

By adding this short snippet of code to your ~/.zshrc you can use peco to navigate the history of your shell:

function exists() { which $1 &> /dev/null }

function peco_select_history() {
    local tac
    exists gtac && tac="gtac" || { exists tac && tac="tac" || { tac="tail -r" } }
    BUFFER=$(fc -l -n 1 | eval $tac | peco --layout=bottom-up --query "$LBUFFER")
    CURSOR=$#BUFFER         # move cursor
    zle -R -c               # refresh
}

zle -N peco_select_history
bindkey '^R' peco_select_history

This is how it looks like when I press CTRL-R and type “man”:

This become really useful when you configure zsh to have a huge history size:

SAVEHIST=10000
HISTSIZE=12000

This is really handy for command that you type over and over and you can’t really script, like pushing Chef files to the chef server.