diff options
Diffstat (limited to 'build-aux/join-v-1')
-rwxr-xr-x | build-aux/join-v-1 | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/build-aux/join-v-1 b/build-aux/join-v-1 new file mode 100755 index 0000000..d1948ac --- /dev/null +++ b/build-aux/join-v-1 @@ -0,0 +1,43 @@ +#!/bin/sh +# join-v-1 - Filter out a set of items from another set of items. + +# Copyright (C) 2021 Free Software Foundation, Inc. +# +# 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 3 of the License, or +# (at your option) any later version. +# +# This 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, see <https://www.gnu.org/licenses/>. + +# Usage: join-v-1 FILE1 FILE2 +# Produces on stdout a list of items that are contained in FILE1 but not +# contained in FILE2. The items are strings without whitespace. +# FILE1 and FILE2 contain such items, one per line, sorted according to +# the current locale. +# FILE1 or FILE2 can be specified as '-', which denotes standard input. + +# The 'join' program does not exist on all platforms. Where it exists, +# we can use it. +if (type join) >/dev/null 2>&1; then + join -v 1 "$1" "$2" +else + # Two solutions based on awk, by Bernhard Voelker <mail@bernhard-voelker.de>. + if true; then + awk -v keyfile="$2" ' + BEGIN { while ((getline < keyfile) > 0) k[$1]=1 } + !k[$1] + ' "$1" + else + awk ' + keys { k[$1]=1; next } + !k[$1] + ' keys=1 "$2" keys=0 "$1" + fi +fi |