For tests, the [[ ]]
construct may be more appropriate than [
]. Likewise, arithmetic comparisons might benefit
from the (( )) construct.
a=8
# All of the comparisons below are equivalent.
test "$a" -lt 16 && echo "yes, $a < 16" # "and list"
/bin/test "$a" -lt 16 && echo "yes, $a < 16"
[ "$a" -lt 16 ] && echo "yes, $a < 16"
[[ $a -lt 16 ]] && echo "yes, $a < 16" # Quoting variables within
(( a < 16 )) && echo "yes, $a < 16" # [[ ]] and (( )) not necessary.
city="New York"
# Again, all of the comparisons below are equivalent.
test "$city" \< Paris && echo "Yes, Paris is greater than $city" # Greater ASCII order.
/bin/test "$city" \< Paris && echo "Yes, Paris is greater than $city"
[ "$city" \< Paris ] && echo "Yes, Paris is greater than $city"
[[ $city < Paris ]] && echo "Yes, Paris is greater than $city" # Need not quote $city.
# Thank you, S.C.
