table of contents
TTHSUM(1) | GNU/Linux | TTHSUM(1) |
NAME¶
tthsum - generates or checks TTH message digestsSYNOPSIS¶
tthsum [-bhmpvVw] [-c [file]] | [file...]DESCRIPTION¶
tthsum generates or checks TTH checksums (roots of the Tiger/THEX hash tree). The Merkle Hash Tree, invented by Ralph Merkle, is a hash construct that exhibits desirable properties for verifying the integrity of files and file subranges in an incremental or out-of-order fashion. tthsum uses the Tiger hash algorithm, by Ross Anderson and Eli Biham, for both the internal and the leaf nodes.. http://www.open-content.net/specs/draft-jchapweske-thex-02.html
. http://www.cs.technion.ac.il/~biham/Reports/Tiger/
OPTIONS¶
- -b
- An md5sum compatibility option. It does absolutely nothing.
(md5sum uses -b to treat binary files differently from texts files.)
- -c
- Check tthsum of all files listed in file against the
checksum listed in the same file. The actual format of that file is the
same as output of tthsum. That is, each line in the file describes
a file. A line looks like:
- -m
- Use mmap(2) instead of read(2) to read the
contents of the files to hash. Normally, using read is cheaper. This all
depends on system load, I/O speed, CPU speed, L1 and/or L2 cache size and
whatnot.
- -p
- Show the progress. Print (<COMPLETED>/<TOTAL>)
every 10 MiB on standard error while hashing. The numbers are in MiB.
- -v
- Be verbose. Print filenames when checking (with -c).
- -w
- Warn on improperly formatted lines when checking (with -c).
- -h, -V
- Print a small help text or the version, respectively, on
standard out. If an unknown combination of options is encountered, the
small help is printed on standard error and tthsum will return
non-zero.
NOTES¶
tthsum intentionally uses an interface identical to md5sum.AUTHOR¶
tthsum and this manpage were written by Walter Doekes (walter@djcvt.net). The hashing code was copied directly from DC++, an open source peer-to-peer file sharing program by Jacek Sieka (jacek@creatio.se) who had based the hashing code on the one used in BCDC++ (a modified DC++) by Dustin Brody (blackclaw@parsoma.net). After version 1.1.0, the hashing code from the Tiger hash authors is used instead, to support big endian architectures and to remove the need for C++ compilers and libraries. The md5sum manpage, written by Juho Vuori (javuori@cc.helsinki.fi), was used as a template. This manpage was proofread by Dustin Brody.RETURN VALUE¶
tthsum returns 0 if no error occurred or, when checking a digest, if at least one line is formatted properly and the TTHs of all properly formatted lines match. tthsum returns 2 if an unknown combination of options is encountered. In all other cases will tthsum return 1.SEE ALSO¶
cksfv(1), md5sum(1), sha1sum(1)28th June 2005 | Walter Doekes |