Canonicalize a file's path i.e. a cross platform readlink

canonical.sh

#!/bin/sh
# eg. dir=$(canonical $0)

canonical() {
  local d="$(\dirname ${1})"
  local f="$(\basename ${1})"
  (
    \cd ${d} >/dev/null 2>&1
    while [ -h "${f}" ] ; do
      \cd $(\dirname $(\readlink ${f})) >/dev/null 2>&1
    done
    \pwd -P
  )
}

just curious what's the diff between

canonical(){

}

and

function canonical {

}

also curious why you are using

${1}

instead of

${0}

?