Append to array from variable

Question

Suppose I declare an array Unix

declare -a Unix=('Debian' 'Red hat' 'Suse' 'Fedora')

I can append to the array as such

Unix=("${Unix[@]}" "AIX")

I introduce another variable a which points to a string naming the earlier Unix variable

a=Unix

Can I append to the array through this second variable? The reason I want to know is I'm trying to write a function which takes a variable that 'points to an array'.

chepner · Accepted Answer · 2014-02-24 13:52:17Z

6

Use the declare builtin. Its argument undergoes expansion before the assignment is performed, so that $a is expanded to the name of the array to update before the assignment takes place.

declare "$a+=( Aix )"

answered Feb 24, 2014 at 13:52

chepner

538k77 gold badges594 silver badges746 bronze badges

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

Comments

Graeme · Accepted Answer · 2014-02-23 23:39:01Z

1

Escape everything so that only a is substituted and all else remains as is, then use eval -

Unix=('Debian' 'Red hat' 'Suse' 'Fedora')
a=Unix
eval "$a=( \"\${$a[@]}\" \"AIX\" )"

edited Feb 23, 2014 at 23:39

answered Feb 23, 2014 at 23:25

Graeme

3,06024 silver badges28 bronze badges

1 Comment

chepner Over a year ago

Unnecessary use of eval: declare "$a+=( AIX )".

Collectives™ on Stack Overflow

Append to array from variable

2 Answers 2

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related