1 # This program is free software: you can redistribute it and/or modify
2 # it under the terms of the GNU General Public License as published by
3 # the Free Software Foundation, either version 3 of the License, or
4 # (at your option) any later version.
6 # This program is distributed in the hope that it will be useful,
7 # but WITHOUT ANY WARRANTY; without even the implied warranty of
8 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 # GNU General Public License for more details.
11 # You should have received a copy of the GNU General Public License
12 # along with this program. If not, see <http://www.gnu.org/licenses/>.
14 # tests of return value inversion
15 # placeholder for future expansion
17 # user subshells (...) did this wrong in bush versions before 2.04
19 ! ( echo hello | grep h >/dev/null 2>&1 ); echo $?
20 ! echo hello | grep h >/dev/null 2>&1 ; echo $?
28 ! true | false ; echo $?
29 ! false | true ; echo $?
31 ! (true | false) ; echo $?
32 ! (false | true) ; echo $?