Quotes

Bash supports various ways to quote arguments: single quotes, double quotes, and a bash-specific method using C-style quotes $'...'. Zx prefers the latter approach.

const name = 'foo & bar'
await $`mkdir ${name}`

Zx automatically escapes and quotes anything within ${...}, so there's no need for additional quotes.

The following examples produce the same, correct result:

await $`mkdir ${'path/to-dir/' + name}`

await $`mkdir path/to-dir/${name}`

Array of arguments

Zx can also accept an array of arguments within ${...}. Each array item will be quoted separately and then joined by a space.

const flags = [
  '--oneline',
  '--decorate',
  '--color',
]
await $`git log ${flags}`

Glob patterns

Because Zx escapes everything inside ${...}, you can't use glob syntax directly. Instead, Zx provides a glob function.

The following example won't work:

const files = './**/*.md'// Incorrect
await $`ls ${files}`

The correct approach:

const files = await glob('./**/*.md')
await $`ls ${files}`

Home dir ~

Zx won't expand the home directory symbol ~ if it's within ${...}. Use os.homedir() for that purpose.

const dir = `~/Downloads`// Incorrect
await $`ls ${dir}`

await $`ls ${os.homedir()}/Downloads` // Correct

await $`ls ~/Downloads` // Correct, ~ is outside of ${...}

Assembling commands

If you're trying to dynamically assemble commands in Zx, you might run into limitations. For instance, the following approach won't work:

const cmd = 'rm'
if (force) cmd += ' -f'
if (recursive) cmd += ' -r'
cmd += ' ' + file

await $`${cmd}`// Incorrect

Zx will escape the entire string, making the command invalid. Instead, assemble an array of arguments and pass it to Zx like this:

const args = []
if (force) args.push('-f')
if (recursive) args.push('-r')
args.push(file)

await $`rm ${args}`