Modifying bash $PATH

Here's some functions to edit the $PATH without leaving crud:

function pathremove()
{
 local P=:$1:; shift
 while [ "$1" ]; do P=${P/:$1:/:}; shift; done
 P=${P#:}; P=${P%:}
 echo ${P}
}

function pathprefix()
{
 local P=$(pathremove $@); shift
 local N=""
 for n in $@; do N=${N}:$n; done
 echo "${N#:}:${P}"
}

function pathsuffix()
{
 local P=$(pathremove $@); shift
 local N=""
 for n in $@; do N=${N}:$n; done
 echo "${P}${N}"
}

Example usage:

export PATH=$(pathsuffix $PATH $HOME/bin /opt/bin)
export PATH=$(pathremove $PATH /sbin)
export LD_LIBRARY_PATH=$(pathprefix $LD_LIBRARY_PATH /opt/lib)