Question

./build_binaries.sh: line 43: [: ==: unary operator expected

I have this line (line 43) in my bash script which looks correct to me, but it keeps throwing error.

if [ ${platform} == "macosx" ]; then

Error:

./foo.sh: line 43: [: ==: unary operator expected

This is on OSX.

Answer 1

The problem is that $platform is an empty string. The usual workaround is to put it in quotes:

if [ "${platform}" == "macosx" ]

Example:

$ unset x
$ [ $x == 3 ]
-bash: [: ==: unary operator expected
$ [ "$x" == "3" ]
$