[LINUX] Simplify the path displayed at the prompt

/ home / username / foo / bar is long

I want to display it at the prompt with ~ / f / bar like fish

View fish source

Source of prompt_pwd

 string replace -ar '(\.?[^/]{'"$fish_prompt_pwd_dir_length"'})[^/]*/' '$1/' $tmp

It has become.

Since string replace is a function of fish, it is reproduced with bash.

function abbr_pwd() {
    local p=$(echo $PWD | sed "s@$HOME@~@")
    local directories=(${p//\// })
    local _n_d=${#directories[@]}
    local _last=${directories[_n_d - 1]}
    local _abbr_pwd=""
    if [ ${directories[0]} != "~" ]; then
        _abbr_pwd=$_abbr_pwd/
    fi
    #Actually if[[ $p =~ (.?[^\/]{1})[^\/]*\/ ]]I want to process with
    for d in "${directories[@]:0:_n_d-1}"; do
        _abbr_pwd=$_abbr_pwd${d:0:1}/
    done
    echo $_abbr_pwd$_last
}

I want to process with a regular expression like the code of fish, but if [[$ p = ~ (.? [^ \ /] {1}) [^ \ /] * \ /]]; then; echo $ { BASH_REMATCH [@]}; fi only got the first match ~. (If you look it up, you can do it)

Replace the directory path / home / username / foo / bar with sed to make it ~ / foo / bar I decomposed the character string with " / ", combined with "/" leaving only the first character except the last part, and added bar at the end to get ~ / f / bar.

In the root path from $ HOME,/is put at the beginning like / usr / share / theme-> / u / s / theme.

However, if it is under a home directory other than your own user (cannot be replaced with $ HOME), it becomes redundant like / h / o (otherUser) / f / bar.

Display on PROMPT

PS1='[\u@\h] $(abbr_pwd $PWD) \$ '

Please play with it as appropriate.