Handled all within awk. Takes the value from $PWD and constructs directory structures and runs commands against them. The gsub() call is not necessary, but added for better visibility.

If a variable DIR is given on the awk command-line, then that directory is used instead:

Just one character longer than the sed version ('FNR==5' versus -n 5p). On my system, without using "exit" or "q", the awk version is over four times faster on a ~900K file using the following timing comparison:

Adding "exit" or "q" made the difference between awk and sed negligible and produced a four-fold improvement over the awk timing without the "exit".

For long files, an exit can speed things up:

I don't know if it's better but works fine :)

Sample command to obtain a list of geographic localization for established connections, extracted from netstat. Need geoiplookup command ( part of geoip package under CentOS)

Email if you disk is over 90% - www.fir3net.com

Get full url via untr.im

Consider this file :

laminate

this

file

with awk

hello to

commandlinefu

I can use awk substring to laminate words :

lamin

this

file

with

hello

comma

Similar to http://www.commandlinefu.com/commands/view/2000/laminate-files-line-by-line

Work for me on CentOS, grep and print ip addresses of ssh bruteforce attempts

If you run this command on a VMWare Virtual Machine, it will return the string "VMware Virtual Platform". If you run it on a physical machine, it will return nothing. Useful for having a script determine if it's running on a VM or not. Of course, you must have dmidecode installed for this to work.

Try it this way in a script: ISVM=$(dmidecode | awk '/VMware Virtual Platform/ {print $3,$4,$5}')

Then test if $ISVM has text in it, or is blank.

You're behind on your TV catch-up, but how far behind? This command tries to open mplayer against all files in the current dir. If it's a video file it will contain ID_LENGTH, which is summed and output in hours, minutes and seconds.

Someone better at awk could probably reduce this down a lot.

draw `vmstat ` data using gnuplot

inputfile.txt is a space-separated textfile, 1st column contains the items (id) I want to put into my SQL statement.

39 = charactercode for single tick '

If inputfile.txt is a CSV-file separated by "," use FS= to define your own field-separator:

worked on ubuntu 9.04 and cygwin with MS netstat

After executing this, click on a window you want to track X Window events in.

Explaination: "xev will track events in the window with the following -id, which we get by greping window information obtained by xwininfo"

Show apps that use internet connection at the moment.

Can be used to discover what programms create internet traffic. Skip the part after awk to get more details, though it will not work showing only unique processes.

This version will work with other languages such as Spanish and Portuguese, if the word for "ESTABLISHED" still contain the fragment "STAB"(e.g. "ESTABELECIDO")

This corrects duplicate output from the previous command.

Can be used to discover what programms create internet traffic. Skip the part after awk to get more details.

Has anyone an idea why the uniq doesn't work propperly here (see sample output)?

I sometimes (due to mismanagement!) end up with files in a git repo which have had their modes changed, but not their content. This one-liner lets me revert the mode changes, while leaving changed-content files be, so I can commit just the actual changes made.