Check if an element is present in a Bash array [duplicate]

Answer 1

Here's another way that might be faster, in terms of compute time, than iterating. Not sure. The idea is to convert the array to a string, truncate it, and get the size of the new array.

For example, to find the index of 'd':

arr=(a b c d)    
temp=`echo ${arr[@]}`
temp=( ${temp%%d*} )
index=${#temp[@]}

You could turn this into a function like:

get-index() {

    Item=$1
    Array="$2[@]"

    ArgArray=( ${!Array} )
    NewArray=( ${!Array%%${Item}*} )

    Index=${#NewArray[@]}

    [[ ${#ArgArray[@]} == ${#NewArray[@]} ]] && echo -1 || echo $Index

}

You could then call:

get-index d arr

and it would echo back 3, which would be assignable with:

index=`get-index d arr`