On July 27, 2004, Chet Ramey released version 3 of Bash. This update fixes quite a number of bug in Bash and adds some new features.
Some of the added features are:
A new, more generalized {a..z} brace expansion operator.
#!/bin/bash
for i in {1..10}
# Simpler and more straightforward than
#+ for i in $(seq 10)
do
echo -n "$i "
done
echo
# 1 2 3 4 5 6 7 8 9 10 |
The ${!array[@]} operator, which expands to all the indices of a given array.
#!/bin/bash
Array=(element-zero element-one element-two element-three)
echo ${Array[0]} # element-zero
# First element of array.
echo ${!Array[@]} # 0 1 2 3
# All the indices of Array.
for i in ${!Array[@]}
do
echo ${Array[i]} # element-zero
# element-one
# element-two
# element-three
#
# All the elements in Array.
done |
The =~ Regular Expression matching operator within a double brackets test expression. (Perl has a similar operator.)
#!/bin/bash
variable="This is a fine mess."
echo "$variable"
if [[ "$variable" =~ "T*fin*es*" ]]
# Regex matching with =~ operator within [[ double brackets ]].
then
echo "match found"
# match found
fi |