Matching using if and then statement

Question

I have a script that assign a list of names to a variable

$a = tom jerry albert yoyo etc 

I need to check if the content of another variable within my script matches one of the names assigned to this variable. How can I do this? My other variable name is $name. So my logic should be.

if  $name contains in $a
   echo  it matches
esle
    echo it does not match 
fi

So is my $name is equal to tom then I like to echo "it matches"

Can you please advice?

Thanks

Answer 1

Ideally you would want to use an array to store the names and iterate over it to test for a match:

#!/bin/bash

contains()
{
    local element
    for element in "${@:2}"; do
        [ "${element}" = "$1" ] && return 0
    done
    return 1
}

a=(tom jerry albert yoyo)

for name in tom to foo; do
    if contains "${name}" "${a[@]}"; then
        echo "${name} matches"
    else
        echo "${name} doesn't match"
    fi
done

---

$ ./t.sh
tom matches
to doesn't match
foo doesn't match

---

You could even pass by "reference" by using variable indirection, that way you only have to pass the name of the array to contains which you want to match against:

contains()
{
    local element
    for element in "${!1}"; do
        [ "${element}" = "$2" ] && return 0
    done
    return 1
}

names=(tom jerry albert yoyo)

for name in tom to foo; do
    if contains "names" "${name}"; then
        echo "${name} matches"
    else
        echo "${name} doesn't match"
    fi
done

Answer 2

You could loop over the $list variable and check for matches, as in the following excerpt:

list="tom jerry albert yoyo etc"

name=tom

for item in $list
do
        if [[ "$item" == "$name" ]]
        then
                echo it matches
        else
                echo it does not match 
        fi
done

Answer 3

For a completely portable solution, you could use case. Something like

case " $list " in
    *" $name "* ) echo "'$name' included in '$list'" ;;
    * ) echo not. ;;
esac

Answer 4

Ok I found the answer

if [[ "$a" =~ "$name" ]] && [ -n "$name" ]; then
   echo it matches
else
echo it does not match
fi

Cheers