this question is not the same as Does the shell support sets?
i know lots of script language support list structure, such as python, python, ruby, and javascript, so what about linux shell?
does shell support such syntax?
for i in list:
do
print i
done
i would first to initialize a list, for example:
ListName = [ item1, item2, ..., itemn ]
then iterate over it
is that possible when programming shell scripts?
It supports lists, but not as a separate data structure (ignoring arrays for the moment).
The for loop iterates over a list (in the generic sense) of white-space separated values, regardless of how that list is created, whether literally:
for i in 1 2 3; do
echo "$i"
done
or via parameter expansion:
listVar="1 2 3"
for i in $listVar; do
echo "$i"
done
or command substitution:
for i in $(echo 1; echo 2; echo 3); do
echo "$i"
done
An array is just a special parameter which can contain a more structured list of value, where each element can itself contain whitespace. Compare the difference:
array=("item 1" "item 2" "item 3")
for i in "${array[@]}"; do # The quotes are necessary here
echo "$i"
done
list='"item 1" "item 2" "item 3"'
for i in $list; do
echo $i
done
for i in "$list"; do
echo $i
done
for i in ${array[@]}; do
echo $i
done
For make a list, simply do that
colors=(red orange white "light gray")
Technically is an array, but - of course - it has all list features.
Even python list are implemented with array
Source: Stackoverflow.com