- unsigned chksum;
- size_t i;
-
- memset (header, 0, sizeof header);
-
- /* Drop confusing and possibly dangerous prefixes from
- FILE_NAME. */
- while (*file_name == '/'
- || !memcmp (file_name, "./", 2)
- || !memcmp (file_name, "../", 3))
- file_name = strchr (file_name, '/') + 1;
- if (*file_name == '\0')
- {
- /* Dropped *everything* from FILE_NAME.
- Should only be possible for a directory. */
- ASSERT (type_flag == '5');
- return true;
- }
- else if (strlen (file_name) > 99)
- {
- printf ("%s: file name too long\n", file_name);
- return false;
- }
-
- /* Fill in header except for final checksum. */
- strlcpy (header, file_name, 100); /* name */
- snprintf (header + 100, 8, "%07o", mode); /* mode */
- strlcpy (header + 108, "0000000", 8); /* uid */
- strlcpy (header + 116, "0000000", 8); /* gid */
- snprintf (header + 124, 12, "%011o", size); /* size */
- snprintf (header + 136, 12, "%011o", 1136102400); /* mtime (2006-01-01) */
- memset (header + 148, ' ', 8); /* chksum */
- header[156] = type_flag; /* typeflag */
- strlcpy (header + 257, "ustar", 6); /* magic */
- strlcpy (header + 263, "00", 3); /* version */
-
- /* Compute and fill in final checksum. */
- chksum = 0;
- for (i = 0; i < 512; i++)
- chksum += (uint8_t) header[i];
- snprintf (header + 148, 8, "%07o", chksum);
-
- /* Write header. */
- return do_write (archive_fd, header, 512, write_error);