cd /

find `pwd` -name '.*' -prune -o \( -name *.h -o -name *.cpp \) -print | cscope -bi-

export CSCOPE_DB=/cscope.out

vim +'set cst'

Found this useful for scripts where I needed to work with the machine's IP. If $DEVICE is not specified, this will return all IPs on the machine. If $DEVICE is set to a network adapter, it will return just that adapter's IP.

Loops over array of a system var, splits its values and puts the values into %A, %B, %C, %D, and so on.

Create array before, like

and

Be sure to replace %A, %B, etc. with %%A, %%B, etc. when using this from inside of batch files.

Many Mac OS X programs, especially those in Microsoft:Office, create ASCII files with lines terminated by CRs (carriage returns). Most Unix programs expect lines separated by NLs (newlines). This little command makes it trivial to convert them.

HTP (HTTP Time Protocol) is an alternative way of getting "good enough" synchronized time. htpdate will give you near-second accuracy.

It works where NTP/SNTP does not because of firewalls and proxies. Of course, if NTP/SNTP can be used, use that instead.

http://www.clevervest.com/twiki/bin/view/HTP

htp is not in Ubuntu!

Simple and fast variant, not using external programs. Another variation:

HashKnownHosts must be off, of course.

I know you can use pidof but with this you can know the specific PID with his command arguments (useful if you're running various proccess with same application)

Actually $! is an internal variable containing PID of the last job in background.

More info: http://tldp.org/LDP/abs/html/internalvariables.html#PIDVARREF

Using $! for job control:

be careful where you execute this from

do a 'sudo ls' beforehand to prime sudo to not ask for your password

lgrep regex [dir]

Shows you all listening tcp/udp ports, and what program has them open(depending on rights)

I can't put the last ^2 with seq, so I reverse it to delete the last +N. So for doing sum(N^2) you have to do sum((N+1)^2). Must be a better way.

This is a command you see mentioned alot by Gentoo monkeys.

They say to use it after every update of GCC, any library you might use and glibc.

They argue that compiling and recompiling everything like this will optimize the system alot more because you are recompiling the entire system (gcc, glibc etc) with nativly compiled versions of themselves. Same goes for all libraries etc.

I doubt the difference in working speed is really worth the hours and hours you end up having your computer compile the same stuff again and again though.

Better -and faster- using bash printf.

'watch' repeatedly (default every 2 seconds, -n 1 => every second) runs a command (here ':', a shorthand for 'true'), displays the output (here nothing) and the date and time of the last run.

I thought it to be obvious but it seemingly is not: to exit use Ctrl-C.

A space-padded version:

Returns yesterday's date in the format yyyyMMdd