在Bash中将分隔的字符串读入数组

Question

I have a variable which contains a space-delimited string:

line="1 1.50 string"

I want to split that string with space as a delimiter and store the result in an array, so that the following:

echo ${arr[0]}
echo ${arr[1]}
echo ${arr[2]}

outputs

1
1.50
string

Somewhere I found a solution which doesn't work:

arr=$(echo ${line})

If I run the echo statements above after this, I get:

1 1.50 string
[empty line]
[empty line]

I also tried

IFS=" "
arr=$(echo ${line})

with the same result. Can someone help, please?

Answer 1

In order to convert a string into an array, please use

arr=($line)

or

read -a arr <<< $line

It is crucial not to use quotes since this does the trick.

Answer 2

试试这个：

arr=(`echo ${line}`);

Answer 3

In: arr=( $line ) . The "split" comes associated with "glob".
Wildcards ( * , ? and [] ) will be expanded to matching filenames.

The correct solution is only slightly more complex:

IFS=' ' read -a arr <<< "$line"

No globbing problem; the split character is set in $IFS , variables quoted.

Answer 4

If you need parameter expansion, then try:

eval "arr=($line)"

For example, take the following code.

line='a b "c d" "*" *'
eval "arr=($line)"
for s in "${arr[@]}"; do 
    echo "$s"
done

If the current directory contained the files a.txt , b.txt and c.txt , then executing the code would produce the following output.

a
b
c d
*
a.txt
b.txt
c.txt

Answer 5

line="1 1.50 string"

arr=$( $line | tr " " "\n")

for x in $arr
do
echo "> [$x]"
done