CODEWITHSUNDEEP
arraysbash
Samoth
Samoth

Reputation: 25

Find exact match of variable within multiple arrays

I'm trying to write a bash code which should get a variable and search within multiple arrays. For example:

$var = site.com

And my arrays are:

array1=(test world myword something bla my.site.com)
array=(google facebook stackoverflow site.com)
array=(music eating video site.com.dev)

The code that I'm trying to run and unfortunately not working is:

#!/bin/bash
if [[ ${array1[*]} =~ "$var" ]]; then
   echo "it's array1"
elif [[ ${array2[*]} =~ "$var" ]]; then 
   echo "it's array2"
elif [[ ${array3[*]} =~ "$var" ]]; then
   echo "it's array3"
fi

The problem here is that it even it return the same array for "site.com", "my.site.com" and "site.com.dev".

What's missing here and how I should write it properly?

Upvotes: 1

Views: 1332

Answers (1)

Charles Duffy
Charles Duffy

Reputation: 295383

=~ is an unanchored regex -- when the right side is quoted, it becomes a substring search. ${array[*]} assembles a string by combining all the entries in your array with the first character in IFS (a space by default) between them. Thus, [[ ${array[*]} =~ "$var" ]] is flattening your array into a string, and doing a substring search on that string.

site.com is a substring of my.site.com and of site.com.dev, so it's expected for it to match.

If you want an efficient, exact-match-only search, invert your arrays to be associative rather than numerically-indexed, and do a key lookup for each.

That is:

#!/usr/bin/env bash
case $BASH_VERSION in ''|[123].*) echo "ERROR: Needs bash 4.0 or newer" >&2; exit 1;; esac

var=site.com

declare -A array1=( [test]=1 [world]=1 [myword]=1 [something]=1 [my.site.com]=1 )
declare -A array2=( [google]=1 [facebook]=1 [stackoverflow]=1 [site.com]=1 )
declare -A array3=( [music]=1 [eating]=1 [video]=1 [site.com.dev]=1 )

if [[ ${array1["$var"]} ]]; then echo "It's array1"
elif [[ ${array2["$var"]} ]]; then echo "It's array2"
elif [[ ${array3["$var"]} ]]; then echo "It's array3"
else echo "Not found"
fi

Upvotes: 3

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