Use the Deno.Command API instead.

Synchronously executes a subprocess, waiting for it to finish and collecting all of its output.

Will throw an error if stdin: "piped" is passed.

If options stdout or stderr are not set to "piped", accessing the corresponding field on SpawnOutput will throw a TypeError.

const { code, stdout, stderr } = Deno.spawnSync(Deno.execPath(), {
args: [
"eval",
"console.log('hello'); console.error('world')",
],
});
console.assert(code === 0);
console.assert("hello\n" === new TextDecoder().decode(stdout));
console.assert("world\n" === new TextDecoder().decode(stderr));