Commands using awk

The arguments of "seq" indicate the starting value, step size, and the end value of the x-range. "awk" outputs (x, f(x)) pairs and pipes them to "graph", which is part of the "plotutils" package.

Displays six rows and five columns of random numbers between 0 and 1. If you need only one column, you can dispense with the "for" loop.

This example calculates the averages of column one and column two of "file.dat". It can be easily modified if other columns are to be averaged.

Another combination of seq and awk. Not very efficient, but sufficiently quick.

"seq 100" outputs 1,2,..,100, separated by newlines. awk adds them up and displays the sum.

"seq 1 2 11" outputs 1,3,..,11.

Variations:

1+3+...+(2n-1) = n^2

1/2 + 1/4 + ... = 1

This loops through all tables and changes their collations to UTF8. You should backup beforehand though in case some data is lost in the process.

Show the number of failed tries of login per account. If the user does not exist it is marked with *.

Just type 'opened' and get all files currently opened for edit.

This command shows if there are any locked AFS volumes.

The output is a list of AFS volume IDs (or nothing if there are none locked).

Takes a input file (count.txt) that looks like:

1

2

3

4

5

It will add/sum the first column of numbers.

This command converts filenames with embedded spaces in the current directory replacing spaces with the underscore ("_") character.

Can pipe to tail or change the awk for for file size, groups, users, etc.

This command will kill all processes using a directory. It's quick and dirty. One may also use a -9 with kill in case regular kill doesn't work. This is useful if one needs to umount a directory.

This adds all new files to SVN recursively. It doesn't work for files that have spaces in their name, but why would you create a file with a space in its name in the first place?

Removes all unversioned files and folders from an svn repository. Also:

will remove those files which svn status ignores. Handy to add to a script which is in your path so you can run it from any repository (a la 'svn_clean.sh').

This was useful to generate random passwords to some webpage users, using the sample code, inside a bash script

works the same as R's t()

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)...

(depending on sudo settings it might be best to run

first to get to a # prompt)

This command is much quicker than the alternative of "sort | uniq -c | sort -n".