Commands using awk

Create a bash function for easy reference

webPassword()

{

echo $1 $2 | md5sum | awk '{print substr($0,0,10)}'

}

alias webpwd=webPassword

Use like this.

webpwd www.commandlinefu.com MyPetNameHere

cut -f1,2 - IP range 16

cut -f1,2,3 - IP range 24

cut -f1,2,3,4 - IP range 24

This command allows you to revert every modified file one-by-one in a while loop, but also after "echo $file;" you can do any sort of processing you might want to add before the revert happens.

Find the unique values of a column utilizing awk.

Credits goes to here (posted by "era"): http://www.unix.com/shell-programming-scripting/77138-awk-print-distinct-col-values.html

executed on SLES 11.2

Watch out if you have several USB drives plugged in: it scans the whole /media/ folder !!! You can replace /media/ by the path of a specific USB drive (something like /media/F77A-530B/)

I use a sound recorder and I want to plug the recorder and grab the most recent sound.

That's what this command does.

Use mv instead of cp to move instead of copy.

Change *.wav to the required file type.

Find out the earliest installation time of a linux system by getting the / filesystem creation time. This example is only valid the os is installed on an ext2/3/4 filesystem.

I think this have worked, could be enhanced.

Lots of fun to run on nfs clients when the server or network connection is having issues

Daemontools[1] won't always properly reap it's children. Sometimes when you need to kill the main svscan process, you want to also clean up all of it's children. The way to do that is to send a signal to the entire process group. It is a bit tricky

[1] http://cr.yp.to/daemontools.html

See the summary.

To get most of you HDD/SSD driver you need to make sure you partition are aligned, if not the speed penalty can be up to 50% slower!

this simple one liner will check to see if each partition start sector is divided by 512

you need to change sda with your driver

if you find the one of your partitions is not aligned use gparted to move the start sector of the partition to be divided of 512

Will split the std input lines into files grouped by the 5th column content.

you could redirect output to /dev/NULL

If your locale has Monday as the first day of the week, like mine in the UK, change the two $7 into $6

This was done in csh.

This is a little trickier than finding the last Sunday, because you know the last Sunday is in the first position of the last line. The trick is to use the NF less than or equal to 7 so it picks up all the lines then grep out any empty lines.