How to build a function that will show a needed list of "echos"?

August 12, 2022

I want to make a function that will check a number between 1-5
and according to number it gets, it will output the amount of echo lines, as in following example:

if number 1 then show: echo "1" 
if number 2 then show: echo "1" echo "2"
if number 3 then show: echo "1" echo "2" echo "3"

echo "1"
echo "2"
echo "3"
echo "4"
echo "5"

I know it can be done the hard way, as following:

#!/bin/bash

if [[ $num = 1 ]]; then
echo "1"
fi

if [[ $num = 2 ]]; then
echo "1"
echo "2"
fi

and so on…

but it will be too long if I will have to do it 50 times. I am sure there is an alternative way for that.

>Solution :

This is possibly more than you need, but it shows you how to count up to a specified number and use that counter to do something "useful".

#!/bin/bash

# Define the function:
function printNumbersTo() {
  local -i number=${1}                 # -i forces the variable into an integer.
  if [ "${number}" != "${1}" ]; then   # Make sure the input parameter was an integer.
    echo "'${1}' is not an integer."
    return 1
  fi

  local -i counter=0
  while [ ${counter} < ${number} ]; do
    ((counter++))
    echo "Number is '${counter}'."
  done
}

# Now call the function:
printNumbersTo 5