In array operator in bash

Question

Is there a way to test whether an array contains a specified element?

e.g., something like:

array=(one two three)

if [ \"one\" in ${array} ]; then
...
f         


        

Answer 1

in_array() {
    local needle=$1 el
    shift
    for el in "$@"; do
        if [ "$el" = "$needle" ]; then
            return 0
        fi
    done
    return 1
}

if in_array 1 1 2 3; then
    echo true
else
    echo false
fi

# alternatively
a=(1 2 3)
if in_array 1 "${a[@]}"; then
...

Answer 2

array="one two three"
if [ $(echo "$array" | grep one | wc -l) -gt 0 ] ; 
  then echo yes; 
fi

If that's ugly, you could hide it away in a function.

Answer 3

In_array() {
    local NEEDLE="$1"
    local ELEMENT

    shift

    for ELEMENT; do
        if [ "$ELEMENT" == "$NEEDLE" ]; then
            return 0
        fi
    done

    return 1
}

declare -a ARRAY=( "elem1" "elem2" "elem3" )
if In_array "elem1" "${ARRAY[@]}"; then
...

A nice and elegant version of the above.