Filter an Array with Patterns#

Overview#

Objective#

We now transition to some basic examples of bash scripting for the purpose of text processing and data munging. In this challenge, we practice reading and filtering an array.

Resources#

Here’s a great tutorial with useful examples related to arrays in Bash.

Task#

You are given a list of countries, each on a new line. Your task is to read them into an array and then filter out (remove) all the names containing the letter ‘a’ or ‘A’.

Input Format#

The input format consists of a list of country names, each on a separate line. The only characters present in the country names will be upper or lower case characters and hyphens.

Output Format#

From the given list, remove the names that contain ‘a’ or ‘A’ in them. If there are no names left after removing these characters, you should display a blank line.

Sample Input#

Namibia
Nauru
Nepal
Netherlands
NewZealand
Nicaragua
Niger
Nigeria
NorthKorea
Norway

Sample Output#

Niger

Explanation#

Niger is the only name that does not contain an ‘a’ or ‘A’.

Solution#

#!/bin/bash
# shellcheck disable=SC2162

while read country; do
    countries+=("$country")
done

for country in "${countries[@]}"; do
    echo "$country" | grep -v -e '[aA]' > /dev/stdout || true
done

Filter an Array with Patterns

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