How to convert command output to an array line by line in bash?

Question

I'm trying to convert the output of a command like echo -e "a b\nc\nd e" to an array.

X=( $(echo -e "a b\nc\nd e") )

Splits the input for every new line and whitespace character:

$ echo ${#X[@]}
> 5

for i in ${X[@]} ; do echo $i ; done
a
b
c
d
e

The result should be:

for i in ${X[@]} ; do echo $i ; done
a b
c
d e

possible duplicate of How do I create an array in bash from a command variable? — Cascabel
– Cascabel, Commented Jan 7, 2012 at 14:31
Someone might be able to find a better duplicate; that's just the most recent one. This question has probably been asked dozens of times. — Cascabel
– Cascabel, Commented Jan 7, 2012 at 14:32

jfMR · Accepted Answer · 2017-11-17 13:08:20Z

17

You need to change your Internal Field Separator variable (IFS) to a newline first.

$ IFS=$'\n'; arr=( $(echo -e "a b\nc\nd e") ); for i in ${arr[@]} ; do echo $i ; done
a b
c
d e

edited Nov 17, 2017 at 13:08

jfMR

25.2k5 gold badges69 silver badges88 bronze badges

answered Jan 7, 2012 at 8:43

SiegeX

141k25 gold badges150 silver badges159 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

phs Over a year ago

Thanks for the explanations. I'm wondering why you use echo -e and not just echo. Any reason?

SiegeX Over a year ago

the -e flag tells echo to interpret backslash escape characters such as \n to output a newline vs a literal \n

Alberto Salvia Novella · Accepted Answer · 2022-02-03 16:09:32Z

4

readarray -t ARRAY < <(COMMAND)

edited Feb 3, 2022 at 16:09

answered Feb 19, 2021 at 1:35

Alberto Salvia Novella

1,33915 silver badges17 bronze badges

Comments

jaypal singh · Accepted Answer · 2012-01-07 08:49:02Z

0

Set the IFS to newline. By default, it is space.

[jaypal:~] while IFS=$'\n' read -a arry; do 
echo ${arry[0]}; 
done < <(echo -e "a b\nc\nd e")
a b
c
d e

answered Jan 7, 2012 at 8:49

jaypal singh

77.6k24 gold badges108 silver badges147 bronze badges

1 Comment

Cascabel Over a year ago

No, by default it is $' \t\n', spaces tabs and newlines.

Collectives™ on Stack Overflow

How to convert command output to an array line by line in bash?

3 Answers 3

2 Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related