CODEWITHSUNDEEP
bash
Guy
Guy

Reputation: 6522

Passing value of a variable to another variable

I'm trying to make a function that will output fibonacci numbers. This is the code:

#!/bin/bash
a1=0;
a2=1;
echo "Vnesi n"
read n
echo $a1
echo $a2
for ((i = 1; i <= $n; i++)) do
    a3=$(($a1+$a2))
    echo $a3
    $a1=$a2
    $a2=$a3
done

When I run it, it gets to to line 10 (echo $a3) and then outputs an error:

1
0
1
1
./fib.sh: line 11: 0=1: command not found
./fib.sh: line 12: 1=1: command not found

Basically what I'm trying to do is to pass value from a2 to a1 and value from a3 to a2. What am I doing wrong here?

Upvotes: 0

Views: 37

Answers (3)

xtraclass
xtraclass

Reputation: 445

a1=$a2

not $a1

otherwise the left side is evaluated and the value (0 or whatever) is used

Upvotes: 0

Emanuele Paolini
Emanuele Paolini

Reputation: 10162

replace

    $a1=$a2
    $a2=$a3

with

    a1=$a2
    a2=$a3

Upvotes: 1

chepner
chepner

Reputation: 531165

Your first variable assignments are correct:

a1=0
a2=1

The second ones incorrectly prefix the left-hand side with a dollar sign:

$a1=$a2   # Should be a1=$a2
$a2=$a3   # Should be a2=$a3

Upvotes: 2

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