bare-operating-system/packages/bare-os-seeder/kernel/bin/join

/* BARE_OS_BIN_API 1.0.0 — bump when staged /bin script semantics change (see developer guide). */
/** Shared helpers for drive-resident /bin scripts (prepended before each command). */
function bareStdin(ctx) {
  return typeof ctx.shellStdin === 'string' ? ctx.shellStdin : ''
}

/** @param {number} mode @param {'file' | 'directory' | 'symlink'} type */
function bareFormatModeString(mode, type) {
  const typeChar = type === 'directory' ? 'd' : type === 'symlink' ? 'l' : '-'
  const perm = mode & 0o777
  const r = (bit) => (perm & bit ? 'r' : '-')
  const w = (bit) => (perm & bit ? 'w' : '-')
  const x = (bit) => (perm & bit ? 'x' : '-')
  return (
    typeChar +
    r(0o400) +
    w(0o200) +
    x(0o100) +
    r(0o040) +
    w(0o020) +
    x(0o010) +
    r(0o004) +
    w(0o002) +
    x(0o001)
  )
}

/** @param {number} mtimeMs @param {number} [nowMs] */
function bareFormatLsMtime(mtimeMs, nowMs) {
  const now = nowMs != null ? nowMs : Date.now()
  const d = new Date(mtimeMs)
  const months = [
    'Jan',
    'Feb',
    'Mar',
    'Apr',
    'May',
    'Jun',
    'Jul',
    'Aug',
    'Sep',
    'Oct',
    'Nov',
    'Dec'
  ]
  const mon = months[d.getMonth()]
  const day = String(d.getDate()).padStart(2, ' ')
  const sixMo = 180 * 24 * 3600 * 1000
  if (Math.abs(now - mtimeMs) > sixMo) {
    const yr = String(d.getFullYear()).padStart(4, ' ')
    return mon + ' ' + day + '  ' + yr
  }
  const hh = String(d.getHours()).padStart(2, '0')
  const mm = String(d.getMinutes()).padStart(2, '0')
  return mon + ' ' + day + ' ' + hh + ':' + mm
}

/** @param {number} size */
function barePosixBlocks(size) {
  return Math.ceil(Number(size) / 512) || 0
}

/**
 * Raw stdout for NUL/binary when **`process.stdout.write`** is missing.
 * If **`ctx.bareOsBinWrite(Uint8Array|string)`** is set (tests / host), use it.
 * @param {Record<string, unknown>} ctx
 * @param {string | Uint8Array} chunk
 * @returns {boolean}
 */
function bareOsEmitRaw(ctx, chunk) {
  if (typeof ctx.bareOsBinWrite === 'function') {
    const b4 = ctx.b4a
    const u8 =
      typeof chunk === 'string'
        ? b4 && typeof b4.from === 'function'
          ? b4.from(chunk)
          : new TextEncoder().encode(chunk)
        : chunk
    ctx.bareOsBinWrite(u8 instanceof Uint8Array ? u8 : new Uint8Array(u8))
    return true
  }
  const w = globalThis.process?.stdout?.write
  if (typeof w === 'function') {
    w.call(globalThis.process.stdout, chunk)
    return true
  }
  return false
}

async function readLines(ctx, path) {
  const b4 = ctx.b4a
  if (path === '-') return bareStdin(ctx).split('\n')
  const b = await ctx.vfs.readFile(path)
  if (!b) return null
  return b4.toString(b).split('\n')
}

function field(line, delim, n) {
  if (delim === null) {
    const parts = line.split(/\s+/)
    return parts[n - 1] != null ? parts[n - 1] : ''
  }
  const parts = line.split(delim)
  return parts[n - 1] != null ? parts[n - 1] : ''
}

function key(line, delim, n) {
  return field(line, delim, n)
}

async function run(ctx, argv) {
  let delim = null
  let f1 = 1
  let f2 = 1
  const paths = []
  for (let i = 1; i < argv.length; i++) {
    const a = argv[i]
    if (a === '-h' || a === '--help') {
      ctx.console.log(
        'usage: join [-t CHAR] [-1 N] [-2 N] FILE1 FILE2\nJoin lines on equal join fields (sorted input).'
      )
      return
    }
    if (a === '-t' && argv[i + 1]) {
      const d = argv[++i]
      delim = d === '\\t' ? '\t' : d.slice(0, 1)
      continue
    }
    if (a === '-1' && argv[i + 1]) {
      f1 = parseInt(argv[++i], 10)
      continue
    }
    if (a === '-2' && argv[i + 1]) {
      f2 = parseInt(argv[++i], 10)
      continue
    }
    if (a.startsWith('-')) {
      ctx.console.error('join: unsupported option ' + a)
      ctx.exitCode = 1
      return
    }
    paths.push(a)
  }
  if (paths.length !== 2) {
    ctx.console.error('usage: join [-t CHAR] [-1 N] [-2 N] FILE1 FILE2')
    ctx.exitCode = 1
    return
  }
  const A = await readLines(ctx, paths[0])
  const B = await readLines(ctx, paths[1])
  if (!A || !B) {
    ctx.console.error('join: missing input file')
    ctx.exitCode = 1
    return
  }
  const trim = (arr) => {
    if (arr.length && arr[arr.length - 1] === '') arr.pop()
    return arr
  }
  const a = trim(A.slice())
  const b = trim(B.slice())
  const sep = delim != null ? delim : ' '
  let i = 0
  let j = 0
  while (i < a.length && j < b.length) {
    const ka = key(a[i], delim, f1)
    const kb = key(b[j], delim, f2)
    const cmp = ka.localeCompare(kb)
    if (cmp < 0) i++
    else if (cmp > 0) j++
    else {
      const k = ka
      let i1 = i
      while (i1 < a.length && key(a[i1], delim, f1) === k) i1++
      let j1 = j
      while (j1 < b.length && key(b[j1], delim, f2) === k) j1++
      for (let ii = i; ii < i1; ii++) {
        for (let jj = j; jj < j1; jj++) {
          ctx.console.log(a[ii] + sep + b[jj])
        }
      }
      i = i1
      j = j1
    }
  }
}