readlink: illegal option -- f

on macOS readlink dosnt work, like in Linux.

readlink should do:

1. iterates along a sequence of symlinks to find the actual file.
2. returns canonicalized name

readlink: illegal option -f
usage: readlink [-n] [file ...]

-f, --canonicalize
              canonicalize  by following every symlink in every component of the given name recursively; 
              all but the last component must exist

readlink -f is used in:

tools/core/install.sh:    webiscmdrootpath="$(readlink -f -- $scriptPath/../../)/"
tools/core/version.sh:    rootpath="$(readlink -f -- $scriptPath/../../)/"
tools/core/update.sh:    webiscmdrootpath="$(readlink -f -- $scriptPath/../../)/"
tools/core/checker.sh:    project_path=$(readlink -f -- "$scriptPath"/../../)
tools/git/cvstree2git.sh:    new_name="$(readlink -f $(pwd))"
tools/git/clone-deps.sh:            logError "Directory '$(readlink -f ../${line})' already exists, but is not a Git repository, skipping."
tools/betamng/config/config.sh:hostnames=$(readlink -f "$thisscriptpath/hostnames")