/** Shared helpers for drive-resident /bin scripts (prepended before each command). */
function bareStdin(ctx) {
  return typeof ctx.shellStdin === 'string' ? ctx.shellStdin : ''
}

function joinDirFile(dir, name) {
  if (!dir || dir === '.') return name
  const d = dir.endsWith('/') ? dir.slice(0, -1) : dir
  return d + '/' + name
}

async function run(ctx, argv) {
  const names = argv.slice(1).filter((a) => !a.startsWith('-'))
  if (!names.length) {
    ctx.console.error('which: missing argument')
    ctx.exitCode = 1
    return
  }
  const pathEnv = ctx.vfs.env.PATH || '/bin'
  const dirs = pathEnv.split(':').filter(Boolean)
  let miss = 0
  for (const cmd of names) {
    if (cmd.includes('/')) {
      const buf = await ctx.vfs.readFile(cmd)
      if (buf != null) ctx.console.log(ctx.vfs.resolveLogical(cmd))
      else miss++
      continue
    }
    let found = false
    for (const dir of dirs) {
      const p = joinDirFile(dir, cmd)
      const buf = await ctx.drive.get(p, { follow: true })
      if (buf) {
        ctx.console.log(p)
        found = true
        break
      }
    }
    if (!found) miss++
  }
  if (miss) ctx.exitCode = 1
}