You can’t kill zombie processes by sending them “kill -9” directly. Because zombies are already dead!
So its better to kill their “parent” process, unless inits init process.
Run following command…
ps -el | grep Z
Look for PPID
F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD 5 Z 0 2756 2755 0 80 0 - 0 exit ? 00:00:00 php-fpm <defunct>
If PPID is not 1 then you are lucky.
You can kill parent process by running following command:
kill -9 2755
Thats it!
When tested on ghostscript version 8.71, conversion was working properly. So we decided to downgrade ghostscript from version 9.05 to 8.71 on our server running Ubuntu 12.04 LS. Below are steps we followed.
Download sources from http://downloads.ghostscript.com/public/
wget http://downloads.ghostscript.com/public/ghostscript-8.71.tar.gz
Uncompress downloaded source code & change to directory.
tar xvf ghostscript-8.71.tar.gz
cd ghostscript-8.71
Configure it (I used all defaults)
./configure
Start compilation with
make
If you encounter following error:
./base/gp_unix.c:148:2: warning: implicit declaration of function ‘gettimeofday’ [-Wimplicit-function-declaration] make: *** [obj/gp_unix.o] Error 1
Compile using
make XCFLAGS=-DHAVE_SYS_TIME_H=1
Finally install compiled binaries using
make install
At this point you will ghostscript will be installed at /usr/local/bin/gs
There are other methods to install old versions also, but compilation is safer alternative IMHO.
rtCamp is working on an exciting project to connect WordPress with conventional newspaper publishing. The project is in early stages and a sample can be seen at http://anandnagri.com/e-paper/22-aug-2012-3/ (Note: you may see some text in images broken if you visit this on Aug 24 or Aug 25 as all images are recreated using ghostscript 8.71 right now)
As configuration files are often full with comments and blank lines reading them inside shell become tedious! Sometimes you just want to quickly recap active configuration option only.
Mostly, comments starts with “#“(hash) or “;” (semicolon).
Below is a command I often use while debugging various configuration files.
For files having comment starting with “;” e.g. php.ini
egrep -v "^([[:space:]]?$|;)" /path/to/file
For files having comment starting with “#” e.g. my.cnf
egrep -v "^([[:space:]]?$|#)" /path/to/file
For lazy bumps… Following can take care of both of above!
egrep -v "^([[:space:]]?$|;|#)" /path/to/file
You may create a local alias for above command! 😉
Just in case you want to save output in a file… just add " > newfilename" to above commands. Passing original filename may not work (and it will be risky too!)
Over the time, file permissions get messy on a linux/mac server. It really annoys (me) to see static files like images have 0755 i.e. executable permission set for them.
You can use following commands to fix permissions:
find . -type d -print0 | xargs -0 chmod 0775 find . -type f -print0 | xargs -0 chmod 0664
I found many scripts and tools to do this job. IMHO, above command does what we really need!
For WordPress
Ideally, on a wordpress site, no files under “wp-content/uploads” directory should be executable. In case of WordPress multisite, it will be “wp-content/blogs.dir” directory.
Its better to fix file-permissions periodically on your WordPress setup.
We already use rsanpshot for backups. But its always feel safe to have more than one kind of backup.
For other type of backup, we use Crashplan. They support all major platforms, provides many options and have their service decently priced. It will take a separate post to list down all things I like about Crashplan so lets get back to work here!
Crashplan on Ubuntu will need Java Runtime (JRE). Crashplan can install it itself but I prefer to have more control over which JRE I end up putting on our server. They have almost 5 version of JAVA for Ubuntu!
Anyway, just run following command as root user or with sudo access:
apt-get install openjdk-7-jre-headless
Next, we will install Crashplan directly.
Go to Crashplan site, select Linux version and copy-download link to grab latest Crashplan version. Crashplan 3.2.1 is latest as of July 2012.
Run following commands to download, uncompress and install CrashPlan or CrashPlan+…
wget http://download.crashplan.com/installs/linux/install/CrashPlan/CrashPlan_3.2.1_Linux.tgz tar -zxvf CrashPlan_3.2.1_Linux.tgz cd CrashPlan-install ./install.sh
If you are using CrashPlan PRO, use following…
wget http://download.crashplan.com/installs/linux/install/CrashPlanPRO/CrashPlanPRO_3.5.3_Linux.tgz tar -zxvf CrashPlanPRO_3.5.3_Linux.tgz cd CrashPlanPRO-install ./install.sh
Installer will ask you for many questions. Just keep hitting enter keys. Defaults options are all good to go ahead!
At this point Crashplan is running on your Ubuntu Server but it’s not backing anything yet! We will use Crashplan’s Desktop edition for Mac to start backup.
If your installation ends with warning:
Your Linux system is currently configured to watch 8192 files in real time.
We recommend using a larger value; see the CrashPlan support site for details
Then you need to tweak sysctl file:
/etc/sysctl.d/custom.conf
Add…
fs.inotify.max_user_watches=1048576
Save changes…
sysctl -p
Go to Crashplan’s site. This time download Crashplan for Mac & Install it.
If you have started Crashplan after installation, quit it.
Open terminal to edit Crashplan config file…
vim /Applications/CrashPlan.app/Contents/Resources/Java/conf/ui.properties
You can use any text-editor in case you don’e like Vim.
Find a line like below:
#servicePort=4243
Change it to:
servicePort=4200
Note that we have changed port number from 4243 to 4200 (in case you thought we just uncomment it!).
Save file. Exit vim.
Create SSH Tunnel from your mac to remote Ubuntu server using a command-like below:
ssh -L 4200:localhost:4243 username@hostname
Replace username and hostname with your a real username on your hostname. You can put your server IP address also.
After you run above command, you will be logged into a shell on your server. Keep it running as its connecting your desktop crashplan to your server crashplan!
Finally, you can start your Crashplan on Mac and configure backup for your Ubuntu Server!
In case you are already using Crashplan to manage your Mac’s local backup:
There is no easy-way to switch between local & remote machines. (Atleast at the time of writing this…)
Yesterday, almost all installations on our test server had been infected by infamous “<?php eval(base64_decode(…)) ?>” code injection.
We have more than 600 demo sites on our test server and cleaning them using any WordPress plugin out there was simply out of the question! Can you imagine logging into each WordPress, installing plugin, then scanning/cleaning up WordPress… for 600+ WordPress sites?
Below is combination of Linux commands we used. Assuming you have logged into a Linux Shell and already have BACKUP of all files (including infected files) lets move ahead!
grep -lr --include=*.php "eval(base64_decode" /path/to/webroot
This is not necessary but its better to check some files manually to confirm if they have malicious code we are looking for. Also we can use this command after running cleanup command to crosscheck if cleanup is really successful.
If above command gives you correct output, execute following command to perform actual cleaning:
grep -lr --include=*.php "eval(base64_decode" /path/to/webroot | xargs sed -i.bak 's/<?php eval(base64_decode[^;]*;/<?phpn/g'
Executing above will remove eval(*) codes. Above command will also generate a backup version of files it will modify. For example, if it removes code from index.php, you will find a new file index.php.bak in same directory with original content of index.php
Now after running above command, you still find some more infected files, then you need to adjust search and replace parameters in for “sed” part. You may also use following command for a “liberal” cleaning at the risk of breaking something. (in case you really break something, like I did, you can jump to “Troubleshooting” section below!)
grep -lr --include=*.php "eval(base64_decode" /path/to/webroot | xargs sed -i.bak '/eval(base64_decode*/d'
Its really though to cover every possible way to protect yourself from such attach in this post.
If you remember, WordPress community faced this kind of issue because of WP-PhpMyAdmin plugin sometime back. In our case, we found some old WordPress demo sites were having that plugin installed.
To remove WP-PhpMyAdmin plugin form all WordPress sites on your server, execute following command:
find /path/to/webroot -name "wp-phpmyadmin" -type d | xargs rm -rf
Above is all we did to get rid of eval(base64_decode(*)) codes from all files on our test server. If this happens again on our server, I will update this post with added info.
Just in case you end up in a mess, below are some useful commands.
Missing <?php tag in the beginning:
To add “<?php: tag in the beginning of index.php files, in case if you remove it accidentally use following command:
find /var/www/ -name "index.php" | grep "/htdocs/index.php" | xargs grep -L "<?php" | xargs sed -i "1s/^/<?php n/"
Don’t worry. If you already have a “<?php ” tag in the beginning, it won’t be added again.
Extra Newlines at the top!
If you find after cleanup, extra newlines at the top of your code, then use following command to remove trailing newlines. Extra newlines creates problem for blog feeds.
find . -name '*.php' -exec sed -i -e :a -e '/^n*$/{$d;N;ba' -e '}' '{}' ;
I hope you will find this stuff useful.
Dropbox is ramping up its service in a big way over the past few days. For starters it has a new design for it’s website. It also has introduced photo-storing features from mobile phones and PCs. These new options by Dropbox are very important as soon it will face competition from Google and Microsoft with their own cloud storage and sync services.
Considering a lot of photos are taken from mobile phones, this could a make or break feature for Dropbox. It helps that Dropbox is not part of a larger company, which allows a lot of third-party apps to work with it. For example you can read how I use Dropbox to automatically store images from my Facebook account.
If you have a Android phone, then download the Dropbox App on it. This will automatically sync your photos from your phone onto your Dropbox account.
Mac and Linux users can also avail of the latest beta build from the forum link below, to photo-storing is enabled on their computers too.
Direct Download Link: Dropbox Beta (Windows) | Dropbox (Android)
Many such issues are solved by using open source alternatives which are not as good as the paid ones. Hence when it comes to gaming, everyone prefers Windows as it supports a lot of games.
Also, another drawback is we do not find a lot of games that run on Linux. 🙁
Penguspy is a website that really good for looking up free Linux based games online.
If you are using Linux, try out Penguspy and do drop in your comments.
Link: Penguspy
Well, after enjoying the power of Windows 7, I decided to go back to some of my favorite Linux flavors. I like testing out different flavors of Linux and my favorite is Ubuntu. I like it because it’s robust, the community is large enough to provide you with help and the software is easily available.
With the new release of Fedora 14, came many online debates about which one is better- Ubuntu or Fedora? So I decided to try out Fedora.
If you have never tried any Linux, I would recommend you to do so now! Here is a quick tutorial which will help you run or install a linux distro using a Flash/Pen Drive.
NOTE: The USB key will be formatted, so don’t forget to backup the data in the USB you’re going to use.
There are many ways to make a USB drive bootable, but the simplest way to do so is using a tool called Linux Live USB Creator which will not only make your Flash Drive bootable, but will also help you extract ISO image and make the Flash Drive ready for Linux Installation. Download Linux Live USB Creator from here and open the software
NOTE: Many Linux Flavors allow you to install the Linux side by side of Windows. If you want to use Ubuntu, then try Wubi. Wubi is a free application which lets you install Ubuntu side by side of Windows without the hassle of booting from a CD or USB Key.
Link: Linux Live USB Creator
I have been using Ubuntu for few years and was searching for a feature-rich download manager for years. Recently, I came across the best platform independent, all-in-one open source download manager named JDownloader which has attractive features, which substitutes the popular Internet Download (Manager for Windows) in most of it’s features.
Installing JDownloaded is pretty simple.
Please follow the steps for direct bundle.
Method 1 : Download the file; unzip it and you can start using it as shown in the screenshot below
Method 2: Download the script and make it executable by the following ways
For beginners, the former method is pretty simple.
NOTE : JDownloader requires Java Runtime Enviroment (jre/jdk) 1.5 or higher. If possible, you should use the latest Java version.
Please share your views on this downloader let me know if there are any other alternative downloaders which you use.
