Check These Out
This command outputs a table of sighting opportunities for the International Space Station. Find the URL for your city here: http://spaceflight.nasa.gov/realdata/sightings/
This one-liner will the *delete* without any further confirmation all 100% duplicates but one based on their md5 hash in the current directory tree (i.e including files in its subdirectories).
Good for cleaning up collections of mp3 files or pictures of your dog|cat|kids|wife being present in gazillion incarnations on hd.
md5sum can be substituted with sha1sum without problems.
The actual filename is not taken into account-just the hash is used.
Whatever sort thinks is the first filename is kept.
It is assumed that the filename does not contain 0x00.
As per the good suggestion in the first comment, this one does a hard link instead:
$ find . -xdev -type f -print0 | xargs -0 md5sum | sort | perl -ne 'chomp; $ph=$h; ($h,$f)=split(/\s+/,$_,2); if ($h ne $ph) { $k = $f; } else { unlink($f); link($k, $f); }'
Play files in shuffle mode with bash and mpg123.
Why bother using big-as-hell stuff like mplayer? This will play all your music files contained in */* (in my case author/song.format) with bash and mplayer showing a nice output.
quoteless
The symlinks command can show status of all symbolic links, including which links are dangling, which symlinks point to files on other file systems, which symlinks use ../ more than necessary, which symlinks are messy (e.g. having too many slashes or dots), etc. Other useful things it can do include removing all dangling links (-d) and converting absolute links to relative links (-c). The path given must be an absolute path (which is why I used $(pwd) in the example command).
This prints a summary of your referers from your logs as long as they occurred a certain number of times (in this case 500). The grep command excludes the terms, I add this in to remove results Im not interested in.
Replaces a string matching a pattern in one or several files found recursively in a particular folder.
gpg command to encrypt a file on the command line.