auto import from //depot/cupcake/@135843
diff --git a/libc/stdio/asprintf.c b/libc/stdio/asprintf.c
new file mode 100644
index 0000000..7379140
--- /dev/null
+++ b/libc/stdio/asprintf.c
@@ -0,0 +1,60 @@
+/* $OpenBSD: asprintf.c,v 1.15 2005/10/10 12:00:52 espie Exp $ */
+
+/*
+ * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdarg.h>
+#include "local.h"
+
+int
+asprintf(char **str, const char *fmt, ...)
+{
+ int ret;
+ va_list ap;
+ FILE f;
+ unsigned char *_base;
+
+ f._file = -1;
+ f._flags = __SWR | __SSTR | __SALC;
+ f._bf._base = f._p = (unsigned char *)malloc(128);
+ if (f._bf._base == NULL)
+ goto err;
+ f._bf._size = f._w = 127; /* Leave room for the NUL */
+ va_start(ap, fmt);
+ ret = vfprintf(&f, fmt, ap);
+ va_end(ap);
+ if (ret == -1)
+ goto err;
+ *f._p = '\0';
+ _base = realloc(f._bf._base, ret + 1);
+ if (_base == NULL)
+ goto err;
+ *str = (char *)_base;
+ return (ret);
+
+err:
+ if (f._bf._base) {
+ free(f._bf._base);
+ f._bf._base = NULL;
+ }
+ *str = NULL;
+ errno = ENOMEM;
+ return (-1);
+}