bash-5.1 distribution sources and documentation

[thirdparty/bash.git] / examples / functions / sort-pos-params

#
#  Chet Ramey <chet.ramey@case.edu>
#
#  Copyright 2001 Chester Ramey
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2, or (at your option)
#   any later version.
#
#   TThis program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software Foundation,
#   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

# Sort the positional parameters.
# Make sure the positional parameters are passed as arguments to the function.
# If -u is the first arg, remove duplicate array members.
sort_posparams()
{
	local -a R
	local u

	case "$1" in
	-u)	u=-u ; shift ;;
	esac

	# if you want the case of no positional parameters to return success,
	# remove the error message and return 0
	if [ $# -eq 0 ]; then
		echo "$FUNCNAME: argument expected" >&2
		return 1
	fi

	# make R a copy of the positional parameters
	R=( "${@}" )

	# sort R.
	R=( $( printf "%s\n" "${R[@]}" | sort $u) )

	printf "%s\n" "${R[@]}"
	return 0
}

# will print everything on separate lines
set -- 3 1 4 1 5 9 2 6 5 3 2
sort_posparams "$@"

# sets without preserving quoted parameters
set -- $( sort_posparams "$@" )
echo "$@"
echo $#

# sets preserving quoted parameters, beware pos params with embedded newlines
set -- 'a b' 'a c' 'x z'

oifs=$IFS
IFS=$'\n'
set -- $( sort_posparams "$@" )
IFS="$oifs"

echo "$@"
echo $#

sort_posparams