June 30th, 2007
Quite a small interest group here, but hey!
UPDATE #3: okay, enough! I’ve now been sent more ways to do CRC32 checksums than you could possibly ever need =)
UPDATE #2: Pascal Terjan points out that the perl-Archive-Zip package contains /usr/bin/crc32, which is a perl script that does exactly what you’d expect. I don’t know how I missed that, I thought I searched for binaries named crc32…
UPDATE: thanks a lot to Eskild, who clued me in to a command-line way to do this using perl:
perl -MDigest -e 'my $dig = Digest->new("CRC-32"); $dig->add(<>); print $dig->hexdigest(),"\n"' FILENAME
for ease of use, you can do:
alias crc32sum="perl -MDigest -e 'my \$dig = Digest->new(\"CRC-32\"); \$dig->add(<>); print \$dig->hexdigest(),\"\n\"'"
and then just do
Anyone who watches fansubbed anime on Linux might be interested in this. As you no doubt have noticed, many groups in recent years have started including checksums in the file names. For some reason, though, they’ve mostly standardized on using CRC32 checksums, not the MD5 or SHA1 we Linux users are more used to seeing. I poked around looking for a Linux app that could do CRC32 checksums and eventually found one: CalcChecksum. It’s a KDE / Qt app, which is a pain, but I couldn’t find anything that was simpler (a simple command line tool would be great). I’ve now packaged it in Cooker and will push it to /contrib/backports for 2007 and 2007 Spring. It works fine and has a pretty simple interface, so now you can checksum your anime . Packagers for other distros might want to take note, and users of other distros should be able to build it pretty easily: on Mandriva it builds and installs fine with a simple configure, make, make install, all you need are the KDE development libraries.
If anyone knows a simpler way to get a CRC32 checksum for a file on Linux, do enlighten me!