Exec File Sync

process.execFileSync — spawn a child process and capture its stdout, synchronously. Modeled on Node's child_process.execFileSync, not execSync: the given file is fork'd + execvp'd directly, with no shell involved — shell metacharacters in args are passed through literally, not interpreted (no injection risk from untrusted arguments, unlike execSync's shell-interpolation behavior).

V1 scope: no options object (no cwd/env/timeout/stdio overrides yet); stdout only — stderr is inherited (goes straight to this program's own stderr as the child runs, not captured into the return value). A non-zero exit status, or the child dying to a signal, throws a plain catchable Error.

// ── basic capture ───────────────────────────────────────────────────────────
const echoArgs: string[] = ['hello', 'from', 'execFileSync']
const out: string = process.execFileSync('/bin/echo', echoArgs)
console.log(out)   // hello from execFileSync

// ── args is optional ─────────────────────────────────────────────────────────
const bare: string = process.execFileSync('/bin/echo')
console.log(bare.length > 0)   // true — just the newline echo prints alone

// ── no shell: metacharacters come back out verbatim ─────────────────────────
const literalArgs: string[] = ['$(whoami); rm -rf /tmp/nothing']
console.log(process.execFileSync('/bin/echo', literalArgs))
// $(whoami); rm -rf /tmp/nothing   — never expanded or executed, just echoed

// ── bare command names resolve via $PATH, like execvp always has ───────────
const pathArgs: string[] = ['resolved', 'via', 'PATH']
console.log(process.execFileSync('echo', pathArgs))
// resolved via PATH

// ── a non-zero exit status throws a catchable Error ─────────────────────────
try {
    process.execFileSync('/usr/bin/false')
    console.log('never printed')
} catch (e) {
    console.log(e.message)   // Command failed with exit code 1: /usr/bin/false
}

// ── explicitly invoking a shell still works — it's just not automatic ──────
const shellArgs: string[] = ['-c', 'echo shell-was-explicit']
console.log(process.execFileSync('/bin/sh', shellArgs))
// shell-was-explicit

View source on GitHubexamples/process/exec_file_sync.ts

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