Effective find

Having been a long time user of find in unix, though I only recently stumbled into some of its more finer usages. Once example would be the usage of the -exec argument. I've spent countless hours piping find to a file, doing a global replace to execute the desired command and running it as a shell script; that I was simply thrilled to find that I could do it all in one single step :) (I only wish I had a little more patience reading the man pages that I would have stumbled into it sooner). Take for example removing those pesky ws_ftp.log files that litter your directories when someone decides to use ws_ftp to ftp files instead of filezilla. Here is how you can get rid them in a single command

find . -type f -name 'WS_FTP.log' -exec rm -f {} \;

Another cool trick to get rid of the Permission denied messages that otherwise fill up the screen when doing global searches is to redirect stderr to /dev/null.

find / -type f -name 'serverindex.xml' -exec grep -l '8100' {} \; 2>/dev/null

One quick note about using cygwin the \; that should terminate the exec portion of the find should actually be \ ; in cygwin or according to the wikipedia even a plain ; will do

The unix paste command

One relatively unknown unix command is paste which I had occasion to use recently. I had to twiddle some data in between 2 fixed length files and the machine did not have vim so that I could use visual block selection and too big to quickly scp to my workstation. With some help from google I discovered paste, which in combination with cut reduced the task to something as simple as this

cut -c 1-32 file1.txt > left
cut -c 48-  file1.txt > right
cut -c 64-108 file2.txt > middle
paste -d '\0' left middle right # do not use the default delimiter instead use null

Finally I managed to refine the entire process into a series of cut and pastes in sequence.

Fun with awk

Recently I was wrangling with a few log files and sed and grep din't cut it and I had to use awk. I've always dreaded the use of awk as it was a programming language onto itself and hence I din't want to burden myself with learning another language that I rarely use. But, my latest interaction with awk left me satisfied and intrigued. Its almost like perl except that it follows a strict structure for just manipulating text and perl as I've learnt the hard way can be used to do anything (its been described as the duct tape that holds the internet together!!)