a little stupid blog » tips-n-tricks

Google plus profile

Juan Martinez — Thu, 14 Jul 2011 14:27:17 +0000

After reading this blog post from Joerg Moellenkamp’s blog, I decided to “emulate” the way he linked to his Google+ Profile. I’m not sure how he did it but here is how I was able to accomplish the same thing using Apache’s .htaccess file and PHP. Like always, there are many ways to skin a cat so your mileage may vary.

Since I already use mod_rewrite, I updated my $DOCUMENT_ROOT/.htaccess file with the following code:

        RewriteRule ^(\+)(/.*)?$    $1.php

Then, I created a PHP script called +.php and placed it in my website’s $DOCUMENT_ROOT path with the following code:

< ?php
   header( 'Location: https://plus.google.com/101324321036313305633' ) ;
?>

All you need to do is replace the URL in the PHP code with your own Google+ Profile page. Since my website URL is alittlestupid.com, I would use http://alittlestupid.com/+ and it will redirect you to my Google+ Profile page. You would obviously have to use your own website’s URL plus the “+” sign.

Find files and calculate total disk space usage

Juan Martinez — Wed, 01 Apr 2009 19:40:09 +0000

At work, I have a Solaris SVM Disk Suite device which houses many end user files. Over the past year, this file system has grown by over 75%. Initially, I was growing the file system as it reached capacity but one thing I noticed over the years as a sysadmin is that users will always use the disk space if its there. Business reasons restrict applying quotas to the file system so I decided to do some upfront grunt work instead.

A few du/find combinations later, I noticed that 80% of the disk space was being consumed by compressed pdf files in gzip format. Furthermore, most of the pdf files were over a year old. These files are certainly candidates for deletion but I will let the business decide that one.

Here is how you can find all gzip’ed files in the current working directory which have not been modified in over a year and calculate the total disk space consumed.

[user@host ~] # uname -a
SunOS host 5.10 Generic_127111-03 sun4u sparc SUNW,Sun-Fire-V890
[user@host ~] # cd /some_filesystem/
[user@host ~] # find . -name ‘*.pdf.gz’ -type f -mtime +365 -ls | awk ‘{ sum += $7 } END { kb = sum / 1024; mb = kb / 1024; gb = mb / 1024; printf “%.0f MB (%.2fGB) disk space used\n”, mb, gb}’

Once you’ve discovered how much disk space those files are consuming, the next step is up to you but if you had too, you could just as easily remove those offending files. I wont go into preaching about having properly backed up host.

Modify the find command to remove the files:

[user@host ~] # find . -name ‘*.pdf.gz’ -type f -mtime +365 -exec rm -rf {} \;

Argument list too long? Pipe stdout to xargs.

[user@host ~] # find . -name ‘*.pdf.gz’ -type f -mtime +365 -print | xargs rm -rf

Like always, your mileage will vary.

How to identify a Solaris non-global zone

Juan Martinez — Mon, 30 Mar 2009 20:22:06 +0000

It wouldn’t take much for an experienced Solaris Admin to figure out the server they have logged into is a Solaris Container aka Non-Global Zone, or “zone” for short.

For those of us who don’t have years of experience and expertise in Solaris Administration under our belts, here is a list of things I have come across which would help you identify if the server you are logging into is a container. Like always, not all of these will apply to your situation or server configuration so, your mileage will vary.

The zonename command shows the hostname instead of printing “global”

non-global-zone# zonename
non-global-zone

You can no longer use SVM commands

non-global-zone# metastat -p
metastat: zonename: Volume administration unavailable within non-global zones

Show other non-global zones if you are not using IPMP

non-global-zone# arp -a | grep SPLA
ce0 non-global-zone 255.255.255.255 SPLA 00:xx:xx:xx:xx:xx
ce0 other-non-global-zone.fqdn 255.255.255.255 SPLA 00:xx:xx:xx:xx:xx
ce0 theglobalzone.fqdn 255.255.255.255 SPLA 00:xx:xx:xx:xx:xx

If only using lofs devices, format returns nothing

non-global-zone# format
Searching for disks…done
No disks found!

lsof no longer works, see lsof FAQ

non-global-zone# lsof
lsof: can’t stat(/devices): No such file or directory

Sparse root zone does not have CLUSTER info

non-global-zone# ls -la /var/sadm/system/admin/CLUSTER
/var/sadm/system/admin/CLUSTER: No such file or directory

A Solaris zone has a zsched process as apposed to a “sched”

non-global-zone# ps -ef | grep zsched

A Solaris zone will not show any global processes when running a ps with a “-Z” option

non-global-zone# ps -ef -Z | grep global
non-global-zone root 25463 29042 0 03:53:04 pts/60 0:00 grep global

Loopback file systems are displayed instead of actual devices under the “Filesystem” column. Compare df output with /etc/vfstab entries. Chances are they will not match if you are using lofs devices.

non-global-zone# df -h

ifconfig shows a virtual loopback and nic interface

non-global-zone# ifconfig -a
lo0:2: flags=2001000849 mtu 8232 index 1
inet 127.0.0.1 netmask ff000000
ce0:2: flags=1000843 mtu 1500 index 2
inet xxx.xxx.xxx.xxx netmask ffffff00 broadcast xxx.xxx.xxx.xxx

mknod no longer works because it cant write to /dev/

non-global-zone# mknod /dev/testing c 4 64
mknod: Not owner

zonecfg can only be run from the global zone

non-global-zone# zonecfg -z test
zonecfg can only be run from the global zone.

zoneadm will only print you the non-global zone

non-global-zone# zoneadm list
pivishk

zlogin can only be run from the global zone

non-global-zone# zlogin other-non-global-zone
zlogin: ‘zlogin’ may only be used from the global zone

prstat does not show you “global” zone usage, just hostname when using “-Z” option

non-global-zone# prstat -Z

Missing /etc/ethers

non-global-zone# ls -la /etc/ethers
/etc/ethers: No such file or directory

dispadmin does not work

non-global-zone# dispadmin -d
dispadmin: Operation not supported in non-global zones

non-global-zone# prtdiag
prtdiag can only be run in the global zone

dumpadm no longer works

non-global-zone# dumpadm
dumpadm: failed to open /dev/dump: No such file or directory

Again, this is not a complete list nor an end all be all list of things that do not work in a Solaris non-global zone. However, what this list does do is aid in identification of a Solaris 10 zone.

If you’ve discovered other things that do not work in a Solaris 10 zone but do in a global zone, please add a comment.

“cd” My Way In Linux Using Bash Function

Juan Martinez — Thu, 19 Apr 2007 08:37:26 +0000

The “cd” binary that comes with most Linux based distros is good and all but this being Linux, I thought I would enhance its features a bit. I decided to create a simple bash function called “cd” which is sourced at startup by my .bashrc file so that every time I run the Linux command “cd”, the present working directory, or “pwd” is printed as well.

“Why would I want such a dumb feature since I should already know where I am going if I am using the “cd” command”, you ask? Glad you asked so I will tell you young grasshoppa’. Currently on my system, when you change directories using the “cd” command, the present working directory is not printed to give you a nice hand holding feeling. So, for example, when you run commands like “cd ..”, “cd -”, or “cd ../../../”, you are kinda left to guess where you might be. In comes my “cd” function.

NOTE: Its important the the function be named “cd” so if you intend to use it, copy and paste everything below to your $HOME/.bashrc file and source it. How to do that is beyond the scope of this article.


# $PWD is printed when $USER changes dirs
# just the way I like it -> jtnez
cd ()
{
     if [ "$1" = "-" ]; then
        builtin cd $1;
     elif [ $# = 0 ]; then
          builtin cd $HOME
          echo $PWD
     else
         builtin cd $1;
         echo $PWD
     fi
}

Thats it. Now every time you use the “cd” command, you will be shown the present working directory. If for some reason you want to use “cd” in a script and don’t want anything printed to screen, in your scripts, use:

\\cd /path/to/directory/here/

In bash, starting a command with a “\” (backwards slash) will remove any previous alias and use the systems binary without any of the whiz bang options we added above. Its a small tip but hey, try it out!

Ok, but how do I install it? No installation necessary, just append the contents of the above code to your $HOME/.bashrc file, log out of your shell then re-login. Thats it!

Prevent Wifi Bandwith Moochers

Juan Martinez — Fri, 03 Feb 2006 11:43:50 +0000

If you have a Wifi network, chances are that an experienced individual can see your network from well beyond the range of your wireless router. You cant do much from preventing said determined individual from “seeing” your network but you can stop 99.9% of the population (the .1% being the NSA, hehe) from gaining access to your wifi network and hogging up all your bandwidth. For you poor souls out there that are still rocking the ‘WEP’ encryption, here is a movie for you… It shows how an “experienced individual” can gain access to your WEP protected network in roughly 10 minutes!

If you don’t want these individuals hogging your bandwidth (to say the least), here are some general things you can do to bring some basic security measures to your shinny new wifi router/access point.

DISCLAIMER: I am by no means, a Wifi security expert. These tips are those collected from my own trial and error and the experience gained while attempting to secure friends and families’ home wireless networks. Some of the things I list below might not be an option with your wifi router and/or hardware. Like always, your mileage may vary.

Basic preventative measures you can take to stop “free loading bandwidth moochers” from abusing your wireless network.

change your factory default admin password
turn off SSID broadcasting
change the default SSID name
turn on WPA or at the very least enable WEP

For the more paranoid out there, you can also:

further filter access via MAC addresses
turn off DHCP and assign static IP’s
authenticate wireless users with FreeRADIUS (WPA Enterprise)
determine the correct placement of your wifi router for minimal outside leakage
turn wifi or hard wired network OFF during long periods of no activity
put a firewall between your LAN and access point

Well, there you have it. At the very least, know that its possible for a determined individual to gain unauthorized access to your wifi network when all you have protecting said network is WEP. Hey, hope all they want to do is check their email…

nLite: Windows Installation Customizer

Juan Martinez — Tue, 10 Jan 2006 08:46:26 +0000

Normally I post tips and tricks about Linux but once in a while I make that leap into the MS Windows world. OK, without further ado, here is a tip for you Windows users out there.

Have you ever wanted to create a custom Windows CD that had your name, product key, timezone and regional settings “automagically” set during the installation? Wouldn’t it be nice to have the latest service packs automatically slipstreamed as well as have all the updated drivers for your system, registry tweaks, and even have a patched UXTheme.dll without doing a thing?

Do you waste countless hours tweaking the default Windows configuration after you do a clean OS install? If so, then nLite (http://www.nliteos.com/index.html) is what you are looking for. (NOTE: I apologize for sounding like an AD. Hey, at the very least, using this tool can and will save you some time. jtnez)

I have personally used this tool to customize a Windows XP installation that included everything mentioned above plus removing some built in software like MSN Messenger, MS Paint and other un-used games and themes. You can even add small apps that you would normally install anyway after a re-installation of windows. The number and size of the apps will obviously depend on how much space you have on your CD-R.

Generally, I include things like a notepad replacement tool (Notepad++), a image viewing tool (Irfanview), my IM app (Trillian), my firewall/AV (ZoneAlarm Suite), and my archiving tools (WinRAR). Its nice to have all these apps stored in your Windows OS CD as apposed to having to load several CD’s. Keep in mind that the additional apps that I add are not integrated into the OS installation like they would if you were to slipstream a service pack or hotfix. They are simply the setup/installation files I would normally run after the default Windows install anyway. Again, its just another time saver.

Keep in mind that if you lose said CD, it will have your Windows CD key built right in if you choose that option during the creation of the custom Windows CD. Meaning, anyone can then install Windows with your license since they will never be prompt to enter the key. Keep that in mind.

Give it a shot, its a sweet tool for all you Windows phreaks out there.

IVR Cheat Sheet

Juan Martinez — Tue, 29 Nov 2005 05:57:24 +0000

Is it just me or do you hate it when you call the phone company, cable provider, or a big wig service shop and get a dumb computer answering the phone? With older systems, entering a simple “0″ would of immediately transfered you to a human. Not so with most modern automated answering systems. Instead, you are greeted with a sometimes annoying computer attempting to sound like a human. Well, Paul English over at http://paulenglish.com/ has a nice little “cheat sheet” that lists all sorts of methods which enable you to speak to a live person, outsourced or not…

Whats an “IVR”? According to Paul English:

The term IVR stands for "Interactive Voice Response", the fancy name for annoying computers who answer most phones these days.

Go to the “IVR Cheat Sheet” and stick it to the man!

View SSL cert from terminal

Juan Martinez — Wed, 23 Nov 2005 18:53:32 +0000

Does your job or your natural curiosity require you to see a sites’ SSL certificate or other web server TLS info? Here a couple nifty ways to view the secure cert for a webserver and POP3 server from the Linux command line. Again, I am assuming that you are familiar with Linux and have the openssl binary installed on your system. Please read the openssl(1) manpage for futher options.

Web server certificate information on port 443 for www.sourceforge.net:

]$ openssl s_client -connect www.sourceforge.net:443

Subsitute www.sourceforge.net with any domain of your choice. While you are at it, script it:

Run it:

]$ ./get-cert.sh www.sourceforge.net

Sample output:

NOTE: Hit “enter” again after you run the script to disconect from the webserver.

POP3 server certificate information for mail.comcast.net on port 995:
```
]$ openssl s_client -connect mail.comcast.net:995 -showcerts
```
Note: If you run the command above, you will be connected to the mail server. To exit, type “quit”.

Why do you even need to know the cert information? Come on, you are asking me? Make up a reason that satisfies you and live with it .

Unique Temporary Filename

Juan Martinez — Tue, 08 Nov 2005 06:35:42 +0000

If you are a Linux/Unix Systems Administrator you have had to create a shell script to do some mundane and repetitive task at one point in your career, for one reason or another. In my personal experience, I have had to create several such shell scripts to accomplish a wide variety of tasks. One thing that I have found to be common among all my shell scripts is the need for unique, yet temporary filename that can be disposed of without a care in the world. Creating a unique filename is very important since you run the risk of erasing and/or appending output to an existing file on your system. Obviously this can have adverse affects and its not what you want to do.

If you are you a shell scripter and you need to create a random, yet unique temporary filename for one of your scripts, here is technique on how I create a random temporary file on my system. Keep in mind that your results will vary since many of the techniques discussed here make use of system wide variables set at startup by your machine. I assume that you have basic knowledge of Linux, shell scripts, and how to execute one.
On to the code:


TEMP_FILE=$HOME/.$(basename $0).$$.$RANDOM

A working shell script using the example code above:

A sample output would yield something similar, but not exactly, too:


]# ./unique_file
/home/user/.unique_file.16090.16402

]# ./unique_file
/home/user/.unique_file.16172.24316

]# ./unique_file
/home/user/.unique_file.16287.26720

etc...

Now lets examine the way we used to create the file. Again, YMWV on your system

Name the Bash shell variable:
```
TEMP_FILE=
```
Set the path to the location of the TEMP_FILE using our $HOME environment variable:
```
$HOME/
```
This will result in /home/user/
Create a hidden file using the output of the name of the script
```
.$(basename $0)
```
This will result in .unique_file
Use the shell’s current process ID using the $$ parameter
```
.$$
```
In my case, this will result in .16287
Add a completely random number in case your program needs more than one temporary file
```
.$RANDOM
```

Again, in my case, this will result in .26720

You can also use date’s + option to add even more randomness/uniqueness to the filename:

TEMP_FILE=$HOME/.$(basename $0).$$.$RANDOM.$(date +%Y%m%d%H%M%S)

Sample output using the above code:

]# ./unique_file
/home/user/.unique_file.16357.2586.20001218010832

Look at the man page for date. I’m too lazy to explain that one

To some extent this might be overkill but I can guarantee a completely unique and random file name 99.99999~% of the time if you use my method above. Happy shell scripting!

My Portable USB Programs

Juan Martinez — Thu, 13 Oct 2005 06:31:48 +0000

This post was sorta inspired from a couple recent questions I was asked by my good buddy Stevie-D. Well, I guess I should say the his questions made me get off my “fourth point of contact” and finally create the post that I have been meaning to do all along. A post about all the portable USB apps that I use on my own USB stick!

What does this do? Well, it allows me to carry a fully customized computing environment to any PC running M$ Windoze. Meaning, I can take my USB stick with me, slap it into an available USB port on the host PC, run all my apps, and have the same friendly and familiar desktop where ever I so choose.

With this post, I not only help my buddy Stevie-D but if I ever loose my USB drive, I can come back and use this post as a reference in an attempt to recreate what I once had. Granted, I would be out a USB drive but… Well, without further ado, here is an ever growing list of all the portable USB apps that have come to call my “512Meg Sandisk Cruzer Mini” home.

For me, these are the “must haves…”

Web Browser: Portable Firefox
IM Client: Trillian with help from Trillian Anywhere
Desktop Replacement: bbLean
Clipboard Manager: CLCL
File Management: xplorer2
SSH Client: PuTTY
SCP Client: WinSCP
Application Launcher: PStart
More on this jewel below.

The “Nice to have…” list

Sticky Notes Replacement: ATnotes
Password Keeper: KeePass
Office Suite: Portable OpenOffice
Graphic Viewer: IrfanView
FTP Client: FileZilla
Notepad Replacement: Notepad++
POP3 Client: nPOP
Port Monitor: TCPView
Remote Desktop: TightVNC
UNIX Tools: UNIX Tools
Text Editor: WinVi
Audio Player: XMPlay
CD Ripper: CDex
PDF Reader: Foxit PDF Reader
Start up monitor: Startup Control Panel

All the apps listed above have their own installation procedure to get them installed on your portable media USB drive. However, most come packaged as a .zip file where all you would have to do is extract the contents to a directory of your choice (prefferably on your USB drive ) and you’re done! When that is not the case, follow the instructions detailed in the respective apps’ website or readme files. I can personally attest that all the apps I have listed here run perfectly fine from my USB drive.

You might also want to consider some of these apps. I don’t use them for one reason or another but you might think otherwise.

PIMs/organizers: EssentialPIM, Sunbird
Email: JBMail , Portable Thunderbird, EmailVoyager, PocoMail PE
Web Authoring: NVU
Chat/IM: MirandaIM

Here is a list of sites where you can get more software to run on your USB drive:

So when it comes to launching these portable apps, what do you do? Use, what I believe, is an essential tool for “happy USB portable app’ing called PStart. When launched, it can be configured to launch any app from a USB drive and even apps installed on your local PC. On my USB drive, I have all my apps in a root directory called “Portable Apps” with each installed app having its own sub-directory. PStart unifies all these sub-directories and creates a one stop launch pad instead of having to tediously navigate into each sub-directory just to launch an app. Anyway, once you use it, you wont go back!

Thats it for now, enjoy!