Reading stdin into a bash array

Question

I want to accomplish the equivalent of:

list=()
while read i; do
  list+=("$i")
done <<<"$input"

with

IFS=$'\n' read -r -a list <<<"$input"

What am I doing wrong?

input=`/bin/ls /`

IFS=$'\n' read -r -a list <<<"$input"

for i in "${list[@]}"; do
  echo "$i"
done

This should print a listing of /, but I'm only getting the first item.

Answer 1

You must use mapfile (or its synonym readarray, which was introduced in bash 4.0):

mapfile -t list <<<"$input"

One read invocation only work with one line, not the entire standard input.

read -a list populate the content of first line of standard in to the array list. In your case, you got bin as the only element in array `list.

Answer 2

for bash versions that do not support mapfile

IFS=$'\n' read -ra list -d '' <<< "$input"

should do the trick

Answer 3

Solution for Bash version 3 (and 4)

I happened to be logged in to a CentOS 5 box running Bash 3 and I had been working on a solution. I’ve already upvoted cuonglm’s answer but I thought I may as well post the solution I came up with that should work with Bash 3 (and 4). I’ve tested it with a file which had a space in its name and another which begins with -.

Instead of

IFS=$'\n' read -r -a list <<<"$input"

simply use command substitution to create and populate the array:

IFS=$'\n' # split on newline only
set -f    # disable globbing
list=($(printf "%s" "$input"))

Note: This won’t work with filenames which have newlines in their name.