shell-base/modules/scripting/path.sh

#!/bin/bash

isAbsPath() {
    if [[ "${1:0:1}" == / || "${1:0:2}" == ~[/a-z] ]]
    then
        echo $1
        return 0
    else
        return 1
    fi
}

# get full absolute path from a current or parent path
function abs_path {
    local target="$1"
    [[ $(isAbsPath $target) ]] && { echo $target; return 0; }
    # echo relative path finding absolute
    if [[ ! $(echo "$target" | sed 's/^\.\..*//') ]]; then
        # echo .. parent directory
        echo "$(dirname "$(pwd)")/${target/..//}" | tr -s /
        return 0
    fi    
    if [[ ! $(echo "$target" | sed 's/^\..*//') ]]; then
        # echo . current directory
        echo "$(pwd)/${target/.//}" | tr -s /
        return 0
    fi    
    # echo simple relative
    echo "$(pwd)/$target" | tr -s /
}

# get full absolute path from a current or parent path
function abs_dir {
    # with no trailing / will assume that is a file
    # and remove it so return only the directory.
    local target="$1"
    [[ ! "$target" == */ ]] && target=$(dirname $target) 
    echo $(abs_path $target)
}