Commands by systemj (7)

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bash shortcut: !$ !^ !* !:3 !:h and !:t
When expanding, bash output the command, so don't be affraid if you type the command. Here is the details: First examples: $echo foo bar foobar barfoo First argument: $echo !$ echo barfoo barfoo (Note that typing echo foo bar foobar barfoo && echo !$, bash substitute !$ with $:1) Last argument: $echo foo bar foobar barfoo && echo !^ echo foo bar foobar barfoo && echo barfoo foo bar foobar barfoo barfoo All the arguments: $echo !* echo foo bar foobar barfoo foo bar foobar barfoo The third argument: $echo foo bar foobar barfoo && echo !:3 echo foo bar foobar barfoo && echo foobar foo bar foobar barfoo foobar You may want to add {} for large numbers: echo !:{11} for example Now with path: $echo /usr/bin/foobar /usr/bin/foobar For the head: $echo !$:h echo /usr/bin /usr/bin And the tail: $echo !$:t echo foobar foobar You also may want to try !:h and !:t or !!3-4 for the third and the fourth (so !!:* == !!:1-$)

Setting reserved blocks percentage to 1%
According to tune2fs manual, reserved blocks are designed to keep your system from failing when you run out of space. Its reserves space for privileged processes such as daemons (like syslogd, for ex.) and other root level processes; also the reserved space can prevent the filesystem from fragmenting as it fills up. By default this is 5% regardless of the size of the partition. http://www.ducea.com/2008/03/04/ext3-reserved-blocks-percentage/

Binary Clock
Create a binary clock.

Add 10 random unrated songs to xmms2 playlist
If you're like me and want to keep all your music rated, and you use xmms2, you might like this command. I takes 10 random songs from your xmms2 library that don't have any rating, and adds them to your current playlist. You can then rate them in another xmms2 client that supports rating (I like kuechenstation). I'm pretty sure there's a better way to do the grep ... | sed ... part, probably with awk, but I don't know awk, so I'd welcome any suggestions.

Capture all plaintext passwords

Change SSH RSA passphrase
Protects your secret identity with a passphrase. OSX 10.6 automatically does key forwarding and can store the passphrase in the keychain. For other OSes, use ssh -A or set ForwardAgent in ssh_config to enable forwarding. Then use ssh-agent/ssh-add.

Rename files in batch

Sorted, recursive long file listing
Tells you everything you could ever want to know about all files and subdirectories. Great for package creators. Totally secure too. On my Slackware box, this gets set upon login: $ LS_OPTIONS='-F -b -T 0 --color=auto' and $ alias ls='/bin/ls $LS_OPTIONS' which works great.

Console clock -- within screen
Configures screen to always display the clock in the last line (has to be configured only once). After that you not only have got the possibility to detach sessions and run them in background, but also have got a nice clock permanently on your screen.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }


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