[bash] How to use mod operator in bash?

I'm trying a line like this:

for i in {1..600}; do wget http://example.com/search/link $i % 5; done;

What I'm trying to get as output is:

wget http://example.com/search/link0
wget http://example.com/search/link1
wget http://example.com/search/link2
wget http://example.com/search/link3
wget http://example.com/search/link4
wget http://example.com/search/link0

But what I'm actually getting is just:

    wget http://example.com/search/link

This question is related to bash modulo arithmetic-expressions

The answer is


You must put your mathematical expressions inside $(( )).

One-liner:

for i in {1..600}; do wget http://example.com/search/link$(($i % 5)); done;

Multiple lines:

for i in {1..600}; do
    wget http://example.com/search/link$(($i % 5))
done

for i in {1..600}
do
    n=$(($i%5))
    wget http://example.com/search/link$n
done

This might be off-topic. But for the wget in for loop, you can certainly do

curl -O http://example.com/search/link[1-600]