Code challenge: Bash prompt path shortener

Question

I implemented a prompt path shortener for bash to be included in the PS1 environment variable, which shortens the working directory into something more compact but still descrip

Answer 1

Another solution with only bash internals, no use of sed

shortpath()                                                                                                                                                                                                                                                                   
{           
    dir=${1%/*} && last=${1##*/}                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                

    res=$(for i in ${dir//\// } ; do echo -n "${i:0:3}../" ; done)                                                                                                                                                                                                            
    echo "/$res$last"                                                                                                                                                                                                                                                         
} 

My previous solution, with bash and sed. it cut each dir in 3 first caracters and add '..' like this: /hom../obo../tmp../exa../bas../

shortpath()
{
        dir=$(dirname $1)
        last=$(basename $1)

        v=${dir//\// } # replace / by  in path
        t=$(printf "echo %s | sed -e 's/^\(...\).*$/\\\1../' ; " $v) 
            # prepare command line, cut names to 3 char and add '..'
        a=$(eval $t) 
            # a will contain list of 3 char words ended with '..' ans separated with ' '

        echo " "$a"/"$last | sed -e 's/ /\//g'
}