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

/* 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
}

/**
 * Subset of POSIX.1-2017 getconf — fixed values for Bare OS (no host sysconf).
 * Unknown names exit with status 1 (matches common getconf for invalid var).
 */

const CONF = {
  PATH_MAX: '4096',
  NAME_MAX: '255',
  /** POSIX minimum for ARG_MAX; Bare uses a conservative cap for runBinCommand argv. */
  _POSIX_ARG_MAX: '4096',
  ARG_MAX: '262144',
  LINE_MAX: '2048',
  /** POSIX.1-2008 */
  _POSIX_VERSION: '200809',
  _POSIX2_VERSION: '200809',
  NGROUPS_MAX: '32',
  OPEN_MAX: '256',
  STREAM_MAX: '256',
  TZNAME_MAX: '32',
  _POSIX_CHOWN_RESTRICTED: '1',
  _POSIX_NO_TRUNC: '1',
  _POSIX_VDISABLE: '0',
  _POSIX_JOB_CONTROL: '0',
  _POSIX_SAVED_IDS: '0',
  /** Bare shell line length (reasonable REPL limit, not a hard kernel cap). */
  BARE_OS_INPUT_LINE_MAX: '8192',
  /** Defaults for simulated pipelines (override with BARE_OS_PIPELINE_* env); see handbook §3. */
  BARE_OS_PIPELINE_MAX_STAGES: '32',
  BARE_OS_PIPELINE_MAX_BYTES: '2097152',
  BARE_OS_PIPELINE_MAX_LINES: '50000',
  /** Default cap for find -exec/-ok invocations per run (override with env). */
  BARE_OS_FIND_EXEC_MAX: '64',
  /** Max lines `yes` prints before stopping (override with BARE_OS_YES_MAX_LINES). */
  BARE_OS_YES_MAX_LINES: '100000',
  /** Max input lines `shuf` will hold in memory (override with BARE_OS_SHUF_MAX_LINES). */
  BARE_OS_SHUF_MAX_LINES: '50000',
  /** Max output chunk files `split` may create (override with BARE_OS_SPLIT_MAX_FILES). */
  BARE_OS_SPLIT_MAX_FILES: '10000',
  /** Comma-separated `ctx.bareOsSyscall` op names implemented in stock booter. */
  BARE_OS_SYSCALL_OPS:
    'readFile,writeFile,readdir,mkdir,stat,unlink,chmod,chdir,getcwd,readlink,symlink,exists,lstat,rmdir,mount,umount,kill',
  /** Encodings accepted by `/bin/iconv` (subset). */
  BARE_OS_ICONV_ENCODINGS: 'UTF-8',
  /** Synthetic process table JSON path (logical VFS). */
  BARE_OS_PROC_PROCESS_TABLE: '/proc/bare_os/process_table.json'
}

async function run(ctx, argv) {
  const args = argv.slice(1).filter((a) => a !== '--')
  let dumpAll = false
  let name = null
  for (const a of args) {
    if (a === '-a') dumpAll = true
    else if (!a.startsWith('-')) name = a
    else {
      ctx.console.error('getconf: unknown option: ' + a)
      ctx.exitCode = 1
      return
    }
  }

  if (dumpAll) {
    for (const k of Object.keys(CONF).sort()) {
      ctx.console.log(k + '\n' + CONF[k])
    }
    ctx.exitCode = 0
    return
  }

  if (!name) {
    ctx.console.error('usage: getconf [-a] system_var')
    ctx.exitCode = 1
    return
  }

  if (Object.prototype.hasOwnProperty.call(CONF, name)) {
    ctx.console.log(CONF[name])
    ctx.exitCode = 0
    return
  }

  ctx.console.error('getconf: ' + name + ': unknown variable')
  ctx.exitCode = 1
}