Node.js SyntaxError: Unexpected end of input

Question

I wrote a function in shell script:

function nodee() {
    node -e "console.log((function() { $@ })());"
}
export -f nodee

And calling it like this:

nodee "var a = 1, b = 2;" "return a + b;"

Then I got an error:

[eval]:1
console.log((function() { var a = 1, b = 2;

SyntaxError: Unexpected end of input
    at Object.<anonymous> ([eval]-wrapper:6:22)
    at Module._compile (module.js:456:26)
    at evalScript (node.js:532:25)
    at startup (node.js:80:7)
    at node.js:902:3

But this is OK:

nodee "var a = 1, b = 2; return a + b;"

Finally, I found declaring nodee like this can fix the issue:

function nodee() {
    node -e "console.log((function() { `echo $@` })());"
}
export -f nodee

But the following two lines printed the same result:

echo "console.log((function() { `echo $@` })());"
echo "console.log((function() { $@ })());"

So, the question is what's the difference between these two lines?

node -e "console.log((function() { `echo $@` })());"
node -e "console.log((function() { $@ })());"

Mac OS X: 10.9.2 & Node.js: 0.10.26

Thanks in advance!

that other guy · Accepted Answer · 2014-05-06 16:51:41Z

$@ is magic in quotes, and results in multiple arguments:

$ set -- foo bar baz
$ printf "Argument: %s\n" "Hello $@ world"
Argument: Hello foo
Argument: bar
Argument: baz world

Since node only expects one argument, it trips up.

What you wanted is $*, which concatenates the parameters without creating multiple arguments:

$ printf "Argument: %s\n" "Hello $* world"
Argument: Hello foo bar baz world

`echo $@` is basically a hacky way of doing the same -- concatening multiple arguments into a single string -- except it'll break in a number of edge cases like with embedded line feeds or globs:

$ set -- "var = 2 * 3;"
$ printf "Argument: %s\n" "Hello $* world"
Argument: Hello var = 2 * 3; world

$ printf "Argument: %s\n" "Hello `echo $@` world"
Argument: Hello var = 2 a.class a.java a.out barcode.png [...] 3; world

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