Create and verify md5 checksum lists from directory trees or single files, to verify downloads under Windows, Mac OS X and Linux.

sfk md5gento=outfile dir [mask] [mask2] [!mask3] [...]
sfk md5gento=outfile -dir dir1 dir2 -file mask1 mask2 !mask3 [...]
 create list of md5 checksums over all files in a folder.
 by default, this also includes all subfolders (recursive tree walk).
 sfk md5gento=md5.dat thedir

sfk md5check=infile [-skip=n] [-skip n]
 verify list of md5 checksums. to speed up verifys by spot checking,
 specify -skip=n: after every checked file, n files will be skipped.
 sfk md5check=md5.dat

sfk md5 [-quiet] [-verify md5sum] file1 [file2 file3 ...]
calculate md5 hash of one or more files, and optionally compare results.
if md5 sums are compared, both a message is issued, and the shell rc
is set to 0 (all equal) or 1 (not equal).

sfk md5 test01.dat
tell md5 sum of test01.dat

sfk md5 test01.dat test02.dat
compare both files, if content is the same.

sfk md5 -quiet -verify 14da96b20e45fd84c46c5b7aef641cb3 test01.dat
check if test01.dat has an md5 matching the one specified.
issues no output, returns a shell return code > 0 on mismatch.

If you're storing backups on DVD or USB stick, you may turn them into
self-verifying archives by adding an md5 list, sfk.exe, and a short
batch file in it's root directory. For example, create a batch file
"90verify.bat" that contains two commands:

91tools\sfk md5check 91tools\md5sum.txt

Then create a directory 91tools, copy sfk.exe into it, and run

sfk md5gento=91tools\md5sum.txt .

Test the whole stuff once before burning, by running 90verify.bat.
Then burn everything onto DVD. Insert the DVD into another PC, 
double-click on 90verify.bat. This way you verify that your DVD 
can be read also on another machine, which is an important test 
for your data's safety.

The md5 checksums for the current sfk distribution binaries are:               28b22751f0a2ad25e4122f1a6bdcd704
sfk156.exe               64a3599a1828abef3f16f3263f9a381a
sfk156-linux.exe         eb42ceb3d37a949cbf92720c1ad1f3bc
sfk156-linux-lib5.exe    89c014f6bd6c6b8f74256da22386e5bc
dview142.exe             b5d2cc0315c3cd1e22b096d4f952d6b0