Sudhi's Script Hacks

These are some of the scripts I wrote to make my life interesting. I contribute it to the world so that others may enjoy.

Most of the scripts come with some sort of help message (--help). If not, the use of the script ought to be evident.

License

Most of the scripts are GPLv2. Some are with a more liberal (BSD) license. Don't ask - its just my preference.

Brief Blurb about Each

mkgetopt

This subdirectory has a standalone Python tool to generate command line parsing code for use in C/C++ programs. It uses getopt_long() and removes tedium around command line processing. It comes with a manpage and examples.

Scripts

Many of these scripts have builtin help (--help); they are identified with a suffix of *. ::

abspath            when you need command line access to os.path.abspath()
isabs              when you need command line access to os.path.isabs()
realpath           when you need command line access to os.path.realpath()
aes-test.sh        Self-test for aes.py (tests various sizes)
mk-raw-vmware.py   The name says it all; make a raw disk with no holes
randmac            Print a semi-random mac address
rename             Rename files based on regex. Yes, its Perl.
rotatedir          Rotate a directory with newest name ending in .0 suffix
xdump              I forget how to use hexdump. Hence this short alias

server-backup      Script I use to backup remote machines via SSH. Customize it for
                   your use case.

aes.py          *  AES encrypt a file in CTR mode with random salt
cert-tool.py    *  Tool to turn you into a light weight X.509 CA
comic2pdf       *  If you have bunch of CBRs and want PDFs instead
deadlinks       *  Show me symlinks that point to non existent files
dos2unix.py     *  Turn CRLF into LF
finddup         *  If you have identical files strewn around in your file system
hexlify         *  hexlificate your stdin

pardu.py        *  Parallel, pure-python version of du. Possibly
                   faster than the native version on your machine. 
                   alias du=pardu.py is the recommended way.

kill.py         *  Cross platform, interactive way to kill processes by name/PID
                   alias kill=kill.py  works very nicely.
                   'q' in the prompt cleanly exits the tool.

rm.py           *  Cross platform, interactive way to remove files
                   alias rm=rm.py  saves you from unwanted pain.
                   'q' in the prompt cleanly exits the tool.

make-tunnel.py  *  Create IPSec tunnels with preshared keys (site-to-site VPN). Tested on
                   Linux, easy to adapt to other OSes.

pingsubnet.py   *  Ping multiple addresses in parallel for a subnet and get results back;
randpass        *  Experiments in generating random passwords
rsync-backup.py *  Backup using rsync and hardlinks
tolower         *  Play with file names and their case. Try 'tolower --help'

ovpn-tool.py

So, you want to run your own OpenVPN server. And then you decide to get adventerous and offer it to your friends and family. Now, you have to worry about authentication and mobile devices. This utility is designed to make your life easy to manage a small OpenVPN server and generate client certs, client configs etc. The generated .ovpn file is also usable on iOS and Android.

Comes with builtin help ovpn-tool.py --help.

OS X Tools

These are some OS X specific tools that make your life interesting.::

mkdmg.sh          Make OS X compressed disk image from a source directory
gone.sh           Nuke your OS X root/boot disk. Use with care :-)

The next set of utilities work with launchd(8) to make their behavior persistent across boots. You can run them in one-shot mode on the command line or use the install option to relegate it to launchd control.::

osx-ipfw.sh       Enable ipfw(8) with a default set of secure rules
osx-noatime.sh    Enable noatime mounts on all disks
osx-ramfs.sh      Put /tmp and /var/run under a RAMFS
osx-randmac.sh    Randomize your MAC address every day. Designed to auto-detect your wifi
                  interface. Run it without any args to see usage.
osx-tuntap.sh     Make your tun-tap driver persistent.

The ramfs.sh and randmac.sh files have been tested to work on OS X Yosemite.

Linux Specific Tools

::

find-usb-disk     List USB disks - for those of us who dislike systemd
linktest.py       Test link status of ethernet interface(s)

kern-build

If you are in the embedded systems world - building and using custom linux kernels, then you'll love
this utility. It allows you to build multiple kernel images from a single source directory. It
took life during the reign of 2.6.12. I've kept it more or less up-to-date through modern 3.x
kernels. Haven't tried it on 4.x yet.

I used it regularly to build kernels for UML, x86 and mips. If you add other Arch's and their
aliases, send me patches.

openbsd-randmac.sh 
------------------
This script is incomplete - it generates a random mac address and sets it on the interface. But, one
needs a place from whence to call this. Haven't figured out exactly where to do that. Patches
welcome.

disablecaps.inf
---------------
A long time ago, I used to do a lot of work on Windows - especially writing ARM instruction set
emulators. And, I wanted a way to disable CapsLock permanently. I figured out this hack to make it
happen. I haven't tested in on a more recent Windows 7/8/10. If you find this useful, drop me a
note.

--
Sudhi