--- /dev/null
+#include <debug.h>
+#include <syscall.h>
+#include "tests/lib.h"
+#include "tests/main.h"
+
+const char *test_name = "child-sort";
+
+unsigned char buf[128 * 1024];
+size_t histogram[256];
+
+int
+main (int argc UNUSED, char *argv[])
+{
+ int handle;
+ unsigned char *p;
+ size_t size;
+ size_t i;
+
+ quiet = true;
+
+ CHECK ((handle = open (argv[1])) > 1, "open \"%s\"", argv[1]);
+
+ size = read (handle, buf, sizeof buf);
+ for (i = 0; i < size; i++)
+ histogram[buf[i]]++;
+ p = buf;
+ for (i = 0; i < sizeof histogram / sizeof *histogram; i++)
+ {
+ size_t j = histogram[i];
+ while (j-- > 0)
+ *p++ = i;
+ }
+ seek (handle, 0);
+ write (handle, buf, size);
+ close (handle);
+
+ return 123;
+}