# -*- mode: sh; -*-
#
# $HeadURL: https://tstotts.net/pubvc/bash-snippets/paths.sh $
# $Id: paths.sh 435 2007-01-18 20:32:26Z tas $
#

#
# Test that a value is in a path variable proper.
#   $1 - PATH variable name
#   $2 - value to test
# Example usage:
#   f_path_test PATH /bin
#   f_path_test MANPATH /usr/local/man
#
f_path_test()
{
    [[ x${!1} != x${!1%${2}:*} ]] && return 0;
    [[ x${!1} != x${!1#*:${2}} ]] && return 0;
    [[ ${!1} = x$2 ]] && return 0;

    return 1
}

#
# Append one or more values to a path variable proper, iff that path
# does not yet contain the value (avoiding duplicates). Does not
# require value to be a valid filesystem path name.
#   $1 - PATH variable name
#   $2.. - values
#
f_path_append()
{
    n=$1; shift;
    
    for p in "$@"; do
	f_path_test $n "${p}" || export ${n}="${!n}:${p}"
    done
}

f_path_prepend()
{
    n=$1; shift;
    
    for p in "$@"; do
	f_path_test $n "${p}" || export ${n}="${p}:${!n}"
    done
}

#
# Append one or more values to a path variable proper, iff that path
# does not yet contain the value (avoiding duplicates) and the value
# is a valid filesystem path name.
#   $1 - PATH variable name
#   $2.. - values
#
f_path_append_name()
{
    n=$1; shift;
    
    for p in "$@"; do
	if [[ -e "${p}" ]]; then
	    f_path_test $n "${p}" || export ${n}="${!n}:${p}"
	fi
    done
}

f_path_prepend_name()
{
    n=$1; shift;
    
    for p in "$@"; do
	if [[ -e "${p}" ]]; then
	    f_path_test $n "${p}" || export ${n}="${p}:${!n}"
	fi
    done
}

# add some user paths should they exist
ps=(/bin /usr/bin /usr/local/bin /opt/bin /opt/local/bin)
f_path_append_name PATH "${ps[@]}"
ps=($HOME/bin)
f_path_prepend_name PATH "${ps[@]}"

# add some admin paths should they exist
ps=(/sbin /usr/sbin /usr/local/sbin /opt/sbin /opt/local/sbin)
f_path_append_name PATH "${ps[@]}"

# Only if these path variable already exist, ensure certain paths for
# searching man and info pages.
ms=(/usr/man /usr/share/man /usr/local/man /usr/local/share/man)
[[ -n "$MANPATH" ]] && f_path_append_name MANPATH "${ms[@]}"
is=(/usr/info /usr/share/info /usr/local/info /usr/local/share/info)
[[ -n "$INFOPATH" ]] && f_path_append_name INFOPATH "${is[@]}"
is=($HOME/.info)
[[ -n "$INFOPATH" ]] && f_path_prepend_name INFOPATH "${is[@]}"

# add some frequent directories to CDPATH for easy cd'ing
export CDPATH='.'
cs=(~ ~/svn_work/)
f_path_append_name CDPATH "${cs[@]}"