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#   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.
#
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#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

# posix-mode alias expansion in command substitutions within other constructs

DATE='Mon Aug 29 20:03:02 EDT 2022'
shopt -s expand_aliases

alias number="echo 123"

echo $(number)
echo $(( $(number) ))
(( $(number) )) ; echo $?

set -o posix
echo $(number)
echo $(( $(number) ))
(( $(number) )) ; echo $?
set +o posix

# have to turn it back on after leaving posix mode
shopt -s expand_aliases

alias my_alias='echo $DATE'

echo $(eval my_alias)
echo $(my_alias)

set -o posix
echo $(eval my_alias)
echo $(my_alias)
set +o posix ; shopt -s expand_aliases

alias e=echo
alias v='e 123'

set -o posix
echo $(v)
echo $(echo before ; v)
echo $(for f in 0; do
echo in for
done; v)
set +o posix ; shopt -s expand_aliases

alias let='let --'

let '1 == 1'
: $(let '1 == 1')

set -o posix
let '1 == 1'
: $(let '1 == 1')
set +o posix ; shopt -s expand_aliases