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The (in)famous "FizzBuzz" programming challenge, answered in a single line of Bash code. The "|column" part at the end merely formats the output a bit, so if "column" is not installed on your machine you can simply omit that part. Without "|column", the solution only uses 75 characters.
The version below is expanded to multiple lines, with comments added.
for i in {1..100} # Use i to loop from "1" to "100", inclusive.
do ((i % 3)) && # If i is not divisible by 3...
x= || # ...blank out x (yes, "x= " does that). Otherwise,...
x=Fizz # ...set x to the string "Fizz".
((i % 5)) || # If i is not divisible by 5, skip (there's no "&&")...
x+=Buzz # ...Otherwise, append (not set) the string "Buzz" to x.
echo ${x:-$i} # Print x unless it is blanked out. Otherwise, print i.
done | column # Wrap output into columns (not part of the test).
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"
}
stty sane resets the tty to basic usable function. The ^J is a newline -- sometimes CR/LF interpretation is broken so use the ^J explicitly.
requires mplayer
This is very helpful to place in a shell startup file and will make grep use those options all the time. This example is nice as it won't show those warning messages, skips devices like fifos and pipes, and ignores case by default.
Source: http://superuser.com/questions/49408/how-do-i-monitor-or-view-the-thread-count-of-a-certain-process-on-aix
Quick and dirty forkbomb for all flavors of windows
Do not use in production. Replace start with a command of your choice, this will just open a new command prompt and is pretty tricky to stop once started
This command lets you see and scroll through all of the strings that are stored in the RAM at any given time. Press space bar to scroll through to see more pages (or use the arrow keys etc).
Sometimes if you don't save that file that you were working on or want to get back something you closed it can be found floating around in here!
The awk command only shows lines that are longer than 20 characters (to avoid seeing lots of junk that probably isn't "human readable").
If you want to dump the whole thing to a file replace the final '| less' with '> memorydump'. This is great for searching through many times (and with the added bonus that it doesn't overwrite any memory...).
Here's a neat example to show up conversations that were had in pidgin (will probably work after it has been closed)...
$sudo cat /proc/kcore | strings | grep '([0-9]\{2\}:[0-9]\{2\}:[0-9]\{2\})'
(depending on sudo settings it might be best to run
$sudo su
first to get to a # prompt)
Converts a single FLAC file with associated cue file into multiple FLAC files.
Takes two arguments: the name of the FLAC file and and the name of the cue file.
Example: flacAlbumToFiles foo.flac foo.cue
Requires:
- cuetools
- shntools
