How can I fix fpmurphy's bash-like customizable prompt?

[rwmills]

In December 2018 Finnbar P. Murphy posted a PS1 discipline function that uses parameter-less macros that customizes the ksh93 shell prompt similar to the way you can in Bash.

I have been using this function in my .kshrc for the last 3 years and have only found 2 problems with it. The /w and /W macros are supposed to replace $HOME with the ~ character but doesn't.

I stumbled upon the following piece of code that replaces $HOME with ~. I have tried to modify the /w and /W macros to do the same but every attempt has failed.

PS1=$'\a\r\a\e[1;34m\a┌─[\a\e[1;34m\a$(
d=${PWD:-?} p=~
d=${d/#$p/\ ~}
print -nr -- "$d"
)\a\e[1;34m\a ] \n└─\a\e[1;34m\a$ \e[0m\a'

Any suggestions as to how to do this will be welcome.

I have attached a copy of Finnbar's posting.

Bash-like Customizable Prompt in
Korn Shell.pdf

[McDutchie]

Some time ago I wrote these discipline functions for my .kshrc:

# RELPWD expands to relative current working directory with ~ support
# and configurable number of pathname components kept
function RELPWD.get
{
        typeset del ellip=$'\u2026' v=$PWD keep=${RELPWD.keep}
        ((${#ellip}==1)) || ellip='...'
        [[ ($v == "$HOME" || $v == "$HOME"/*) && $HOME != / ]] && v=\~${v#"$HOME"}
        if      [[ -n $keep ]]
        then    del=${v%/$keep}/
                [[ $v == /*/$keep ]] && v=$ellip/${v#"$del"}
                [[ $v == \~/*/$keep ]] && v=\~/$ellip/${v#"$del"}
        fi
        .sh.value=$v
}
# convert <=1 to *, 2 to */*, 3 to */*/*, etc.
function RELPWD.keep.set
{
        typeset -si i n
        let "(n=${.sh.value}) ? 1 : 1" 2>/dev/null || n=2
        ((n>64)) && n=64   # sanity check
        ((n<1)) && .sh.value='' && return
        .sh.value='*'
        for ((i=2; i <= n; i++))
        do      .sh.value+='/*'
        done
}
# change this anytime to set number of pathname components kept
# set to 0 to keep all (but still change your home directory to ~)
RELPWD.keep=2

Now that you have $RELPWD you can quite simply replace the \w and \W entries in Finnbarr's code:

                w)      var+="\$RELPWD";;
                W)      var+="\$(basename \"\$RELPWD\")";;

To get the exact same behaviour as bash (i.e., don't replace any leading components by an ellipsis), set RELPWD.keep=0. You can change that variable on the fly to experiment with it, the $RELPWD output changes immediately.

Hope this helps :)

[rwmills]

It definitely did help. Thanks very much.
BTW Is there an ETA for 1.1?

[McDutchie]

Not yet, sorry. My top priority is getting 1.0.11 out first, from the 1.0 branch. But please do feel free to build ksh from the dev branch, test it, and report any bugs you find! Let me know if you need a hand with building it.