+
+void
+compare_bytes (const void *read_data_, const void *expected_data_, size_t size,
+ size_t ofs, const char *filename)
+{
+ const uint8_t *read_data = read_data_;
+ const uint8_t *expected_data = expected_data_;
+ size_t i, j;
+ size_t show_cnt;
+
+ if (!memcmp (read_data, expected_data, size))
+ return;
+
+ for (i = 0; i < size; i++)
+ if (read_data[i] != expected_data[i])
+ break;
+ for (j = i + 1; j < size; j++)
+ if (read_data[j] == expected_data[j])
+ break;
+
+ quiet = false;
+ msg ("%zu bytes read starting at offset %zu in \"%s\" differ "
+ "from expected.", j - i, ofs + i, filename);
+ show_cnt = j - i;
+ if (j - i > 64)
+ {
+ show_cnt = 64;
+ msg ("Showing first differing %zu bytes.", show_cnt);
+ }
+ msg ("Data actually read:");
+ hex_dump (ofs + i, read_data + i, show_cnt, true);
+ msg ("Expected data:");
+ hex_dump (ofs + i, expected_data + i, show_cnt, true);
+ fail ("%zu bytes read starting at offset %zu in \"%s\" differ "
+ "from expected", j - i, ofs, filename);
+}
+
+void
+exec_children (const char *child_name, pid_t pids[], size_t child_cnt)
+{
+ size_t i;
+
+ for (i = 0; i < child_cnt; i++)
+ {
+ char cmd_line[128];
+ snprintf (cmd_line, sizeof cmd_line, "%s %zu", child_name, i);
+ CHECK ((pids[i] = exec (cmd_line)) != PID_ERROR,
+ "exec child %zu of %zu: \"%s\"", i + 1, child_cnt, cmd_line);
+ }
+}
+
+void
+join_children (pid_t pids[], size_t child_cnt)
+{
+ size_t i;
+
+ for (i = 0; i < child_cnt; i++)
+ {
+ int status = join (pids[i]);
+ CHECK (status == (int) i,
+ "join child %zu of %zu returned %d (expected %d)",
+ i + 1, child_cnt, status, i);
+ }
+}