New utils

kernel/bin/base64

@@ -0,0 +1,210 @@
+/* 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
+}
+
+/**
+ * base64 — encode or decode Base64 (RFC 4648).
+ * Uses btoa/atob or Buffer when available; otherwise a small inline encoder.
+ */
+function bareB64EncodeBytes(u8) {
+  const B = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
+  let out = ''
+  let i = 0
+  for (; i + 2 < u8.length; i += 3) {
+    const n = (u8[i] << 16) | (u8[i + 1] << 8) | u8[i + 2]
+    out += B[(n >> 18) & 63] + B[(n >> 12) & 63] + B[(n >> 6) & 63] + B[n & 63]
+  }
+  const rest = u8.length - i
+  if (rest === 1) {
+    const n = u8[i] << 16
+    out += B[(n >> 18) & 63] + B[(n >> 12) & 63] + '=='
+  } else if (rest === 2) {
+    const n = (u8[i] << 16) | (u8[i + 1] << 8)
+    out += B[(n >> 18) & 63] + B[(n >> 12) & 63] + B[(n >> 6) & 63] + '='
+  }
+  return out
+}
+
+function bareB64DecodeToU8(s) {
+  const t = String(s).replace(/\s+/g, '')
+  if (typeof globalThis.Buffer !== 'undefined') {
+    return new Uint8Array(globalThis.Buffer.from(t, 'base64'))
+  }
+  if (typeof globalThis.atob === 'function') {
+    const bin = globalThis.atob(t)
+    const out = new Uint8Array(bin.length)
+    for (let i = 0; i < bin.length; i++) out[i] = bin.charCodeAt(i) & 255
+    return out
+  }
+  throw new Error('base64 decode requires Buffer or atob')
+}
+
+async function run(ctx, argv) {
+  let decode = false
+  let wrap = 76
+  const paths = []
+  for (let i = 1; i < argv.length; i++) {
+    const a = argv[i]
+    if (a === '-h' || a === '--help') {
+      ctx.console.log(
+        'usage: base64 [-d] [-w COLS] [FILE]\n' +
+          '       base64 --decode [-w COLS] [FILE]\n' +
+          'Default: encode stdin or FILE; -d/--decode decodes to raw bytes on stdout.'
+      )
+      ctx.exitCode = 0
+      return
+    }
+    if (a === '-d' || a === '--decode') {
+      decode = true
+      continue
+    }
+    if ((a === '-w' || a === '--wrap') && argv[i + 1]) {
+      wrap = Number.parseInt(argv[++i], 10)
+      if (!Number.isFinite(wrap) || wrap < 0) wrap = 0
+      continue
+    }
+    if (a.startsWith('-')) {
+      ctx.console.error('base64: unsupported option ' + a)
+      ctx.exitCode = 1
+      return
+    }
+    paths.push(a)
+  }
+  const b4 = ctx.b4a
+  let buf
+  if (!paths.length || paths[0] === '-') {
+    buf = b4.from(bareStdin(ctx))
+  } else {
+    const b = await ctx.vfs.readFile(paths[0])
+    if (!b) {
+      ctx.console.error('base64: cannot read ' + paths[0])
+      ctx.exitCode = 1
+      return
+    }
+    buf = b instanceof Uint8Array ? b : new Uint8Array(b)
+  }
+  if (decode) {
+    const text = new TextDecoder().decode(buf)
+    let raw
+    try {
+      raw = bareB64DecodeToU8(text)
+    } catch (e) {
+      ctx.console.error('base64: ' + (e.message || e))
+      ctx.exitCode = 1
+      return
+    }
+    if (!bareOsEmitRaw(ctx, raw)) {
+      ctx.console.error(
+        'base64: decode output requires process.stdout.write or ctx.bareOsBinWrite'
+      )
+      ctx.exitCode = 1
+    }
+    return
+  }
+  let enc
+  if (typeof globalThis.btoa === 'function') {
+    let s = ''
+    const step = 0x8000
+    for (let i = 0; i < buf.length; i += step) {
+      const chunk = buf.subarray(i, i + step)
+      s += String.fromCharCode.apply(null, chunk)
+    }
+    enc = globalThis.btoa(s)
+  } else {
+    enc = bareB64EncodeBytes(buf)
+  }
+  if (wrap > 0) {
+    const lines = []
+    for (let i = 0; i < enc.length; i += wrap) {
+      lines.push(enc.slice(i, i + wrap))
+    }
+    ctx.console.log(lines.join('\n'))
+  } else {
+    ctx.console.log(enc)
+  }
+}