CODEWITHSUNDEEP
bashshellunixsh
phenolholic
phenolholic

Reputation: 1

How to sequence through sets of numbers in shell/bash

I would like to sequence through a set of numbers.

A simple example is sequence through 2 numbers, then sleep for 5 seconds before proceeding to the next 2.

For example: 1 2 (sleeping for 5 seconds) 3 4 (sleeping for 5 seconds)

Thank you in advance

Upvotes: 0

Views: 201

Answers (3)

Jeffrey Cash
Jeffrey Cash

Reputation: 1073

If your set of numbers is not a simple set of ascending integers like anubhava's response, you can do similar things.

For example, if your sequence is in a list, list.txt:

declare -ai a=($(<list.txt));  ## Read the sequence from list.txt into a
declare -i i l=${#a[@]};
for ((i=0; i<l; i+=2)); do
    echo ${a[i]} ${a[i+1]};
    sleep 5;
done;

If your sequence's numbers are in a string, like s='1,2,3,4,5,6,4,32,25,4,6,4', you could do declare -ai a=(${s//,/ }) to fill a with your numbers.

Upvotes: 0

codeforester
codeforester

Reputation: 42999

You could do this as well, using the modulo operator %:

declare -i max_value=10 # set it whatever you want
for ((i = 1; i < $max_value; i++)); do
  printf "Number is: $i\n"
  [[ $(( $i % 2 )) == 0 ]] && printf "Sleeping\n" && sleep 5  # sleep when the number is even
  # do whatever...
done

Output:

Number is: 1
Number is: 2
Sleeping
Number is: 3
Number is: 4
Sleeping
Number is: 5
Number is: 6
Sleeping
Number is: 7
Number is: 8
Sleeping
Number is: 9

Upvotes: 0

anubhava
anubhava

Reputation: 785146

You can use this for loop in bash:

for ((i=1; i<10; i+=2)); do echo $i $((i+1)); sleep 5; done

1 2
3 4
5 6
7 8
9 10

Upvotes: 1

Related Questions