Just for the record (for other newbies as I am), it turns out that the best
approach is to actually check in the C source code what is the actual size for
each field. So in the original source code I added lines like this:
printf("\nversion: %d version_needed: %d flag: %d\n",
sizeof(file_info.version), sizeof(file_info.version_needed),
sizeof(file_info.flag));
printf("compression_method: %d dosDate: %d crc: %d\n",
sizeof(file_info.compression_method), sizeof(file_info.dosDate),
sizeof(file_info.crc));
printf("compressed_size: %d uncompressed_size: %d size_filename:
%d\n", sizeof(file_info.compressed_size), sizeof(file_info.uncompressed_size),
sizeof(file_info.size_filename));
printf("size_file_extra: %d\n", sizeof(file_info.size_file_extra));
printf("size_file_comment: %d\n", sizeof(file_info.size_file_comment));
printf("size_file_comment: %d\n", sizeof(file_info.size_file_comment));
Run
As consequence, I realized that the appropriate sizes were:
tm_unz* = object
tm_sec:uint32 #; /* seconds after the minute - [0,59] */
tm_min:uint32 # ; /* minutes after the hour - [0,59] */
tm_hour:uint32 #; /* hours since midnight - [0,23] */
tm_mday:uint32 #; /* day of the month - [1,31] */
tm_mon:uint32 #; /* months since January - [0,11] */
tm_year:uint32 #; /* years - [1980..2044] */
# uLong (4 bytes): uint32
unz_file_info64* = ref object #{.packed.}
version:uint64 # version made by 2 bytes
// uLong
version_needed:uint64 # version needed to extract 2 bytes
// uLong
flag:uint64 # general purpose bit flag 2
bytes // uLong
compression_method:uint64 # compression method 2 bytes
// uLong
dosDate:uint64 # last mod file date in Dos fmt 4 bytes
// uLong
crc:uint64 # crc-32 4 bytes
// uLong
compressed_size:uint64 # compressed size 8 bytes
// ZPOS64_T
uncompressed_size:uint64 # uncompressed size 8 bytes
// ZPOS64_T 329385
size_filename:uint64 # filename length 2
bytes // uLong
size_file_extra:uint64 # extra field length 2
bytes // uLOng
size_file_comment:uint64 # file comment length 2
bytes // uLong
disk_num_start:uint64 # disk number start 2 bytes
// uLong
internal_fa:uint64 # internal file attributes 2 bytes
// uLong
external_fa:uint64 # external file attributes 4 bytes
// uLong
tmu_date:tm_unz # tm_unz
Run
