referring to an array outside of a loop

Question

So I have something that looks like this:

a=1
declare -a array
cat ~file | while read line
do
array[$a]=$line
let a=$a+1
echo ${array[(($a - 1))]}
done

read n
m=$n
echo ${array[$m]}

When I echo the array in the loop, it works, but when I try to refer to it outside of the loop, it does not work. Can someone please tell me why? The second echo does not return the value of the array.

score 0 · Accepted Answer · answered Feb 26 '14 at 14:07

0

This is because the data is being stored inside a sub-shell, as you do cat ~file | while ....

To prevent it, do: while do ... done < file. Also, note that you can increment with a simple $((a+1)) or even $((a ++)):

a=1
declare -a array
while read line
do
   array[$a]=$line
   $((a+1))
   echo ${array[(($a - 1))]}
done < ~file

answered Feb 26 '14 at 14:07

fedorqui

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Hi, when I tried this, it gives me a syntax error at 'done' "unexpected token"? – user3351901 Feb 26 '14 at 14:18
I guess you can also use the syntax described in http://stackoverflow.com/q/1951506/1983854 , that is `array+=($line)` – fedorqui Feb 26 '14 at 14:24

referring to an array outside of a loop

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