test='^[0-9]+$'
if ! [[ $YOURNUM =~ $test ]] ; then
echo "no"
else
echo "yes"
fi
if ! [[ $YOURNUM =~ $test ]] ; then
echo "no"
else
echo "yes"
fi
2018-02-10
if [ 1 ]
then
order1
elseif [ 2 ]
then
order2
else
order3
fi
then
order1
elseif [ 2 ]
then
order2
else
order3
fi
2018-02-02
ps aux | grep "httpd" | grep -v grep
2018-02-02