Updates

kernel/bin/xargs

@@ -60,9 +60,121 @@ function barePosixBlocks(size) {
   return Math.ceil(Number(size) / 512) || 0
 }
 
+/**
+ * Bounded xargs for Bare OS: invokes ctx.runBinCommand only (no host spawn).
+ * Limits: stdin 256KiB, 4096 whitespace/null tokens, 128 args per invocation,
+ * 64 invocations per run. Exceeding limits is a fatal error (exit 125).
+ */
+
+const MAX_STDIN = 256 * 1024
+const MAX_TOKENS = 4096
+const MAX_PER_INVOCATION = 128
+const MAX_INVOCATIONS = 64
+
 async function run(ctx, argv) {
-  ctx.console.error(
-    'xargs: running arbitrary commands from /bin/xargs is not supported in Bare OS; use the shell to expand arguments.'
-  )
-  ctx.exitCode = 1
+  if (typeof ctx.runBinCommand !== 'function') {
+    ctx.console.error(
+      'xargs: ctx.runBinCommand is not available (requires a Bare OS booter session)'
+    )
+    ctx.exitCode = 1
+    return
+  }
+  const args = argv.slice(1)
+  let nullSep = false
+  let maxBatch = MAX_PER_INVOCATION
+  let i = 0
+
+  while (i < args.length && args[i].startsWith('-')) {
+    const a = args[i]
+    if (a === '--') {
+      i++
+      break
+    }
+    if (a === '-0' || a === '--null') {
+      nullSep = true
+      i++
+      continue
+    }
+    if (a === '-n' || a === '--max-args') {
+      const n = args[i + 1]
+      if (n == null || !/^\d+$/.test(n) || Number(n) < 1) {
+        ctx.console.error('xargs: -n requires a positive integer')
+        ctx.exitCode = 1
+        return
+      }
+      maxBatch = Math.min(Number(n), MAX_PER_INVOCATION)
+      i += 2
+      continue
+    }
+    if (a.startsWith('-n') && a.length > 2 && /^\d+$/.test(a.slice(2))) {
+      const n = Number(a.slice(2))
+      maxBatch = Math.min(n, MAX_PER_INVOCATION)
+      i++
+      continue
+    }
+    ctx.console.error('xargs: unsupported option: ' + a)
+    ctx.console.error(
+      'xargs: Bare OS supports: -0/--null, -n N (max ' +
+        MAX_PER_INVOCATION +
+        ' per run)'
+    )
+    ctx.exitCode = 1
+    return
+  }
+
+  /** @type {string[]} */
+  let cmd = args.slice(i)
+  if (cmd.length === 0) cmd = ['echo']
+
+  let text = bareStdin(ctx) || ''
+  if (text.length > MAX_STDIN) {
+    ctx.console.error(
+      'xargs: stdin exceeds ' + MAX_STDIN + ' bytes (Bare OS limit)'
+    )
+    ctx.exitCode = 125
+    return
+  }
+
+  /** @type {string[]} */
+  let pieces
+  if (nullSep) {
+    pieces = text.split('\0').filter((s) => s.length > 0)
+  } else {
+    pieces = text.trim() === '' ? [] : text.trim().split(/\s+/).filter(Boolean)
+  }
+
+  if (pieces.length > MAX_TOKENS) {
+    ctx.console.error(
+      'xargs: too many arguments (' + pieces.length + ' > ' + MAX_TOKENS + ')'
+    )
+    ctx.exitCode = 125
+    return
+  }
+
+  const runOne = async (batch) => {
+    await ctx.runBinCommand(cmd.concat(batch))
+  }
+
+  if (pieces.length === 0) {
+    await runOne([])
+    return
+  }
+
+  let invocations = 0
+  for (let o = 0; o < pieces.length; o += maxBatch) {
+    if (++invocations > MAX_INVOCATIONS) {
+      ctx.console.error(
+        'xargs: exceeded ' + MAX_INVOCATIONS + ' invocations (Bare OS limit)'
+      )
+      ctx.exitCode = 125
+      return
+    }
+    const batch = pieces.slice(o, o + maxBatch)
+    await runOne(batch)
+    const ec = Number(ctx.exitCode) || 0
+    if (ec !== 0) {
+      ctx.exitCode = ec
+      return
+    }
+  }
 }