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Upgrading OpenSuSE 13.1 to 13.2 – My Experience

OpenSuSE 13.1 Upgrade to 13.2.

OpenSuSE Linux UpgradeI am an happy user of OpenSuSE Linux that I have installed on my Laptop PC as follows:

  • I have installed Oracle VirtualBox on Windows 8,1
  • I have installed OpenSuSE Linux within VirtualBox and soon I am going to install also Linux Mint

This approach has, in my opinion, a few advantages as follows:

  • I don’t need to reboot to work in Linux or Windows
  • I can access applications in both environments

Recently I have decided to upgrade my OpenSuSe installation from 13.1 to 13.2 and I have followed the suggestions of an article published in the Unixmen.com website that I have re-published it below for your convenience.

 

How To Upgrade To openSUSE 13.2 From openSUSE 13.1

The upgrade process took a pretty long time, but I didn’t experience any serious problem.

Sometimes some of the packages upload did not complete, but it completed OK after answering r (retry) to the error message.

However when I tried to start the upgraded version of my OpenSuSE Linux the screen window was pretty small and I had problems to find a way to expand it.

Finally I discovered the the Linux upgrade had installed the version 5 of the VirtualBox Guest modules, whereas my Oracle VirtualBox was still at version 4.

I upgraded therefore also the VirtualBox from 4.3.12 to the latest version 5.1.12 and after that everything worked correctly.

Finally everything worked correctly and I was also satisfied to notice that the combination of the new versions of Oracle VirtualBox and Linux OpenSuSE 13.2 produced better response times than the previous versions. The results were well worth the effort,

 

A Video on How to Change the Screen Resolution in VirdtualBox

References

How To Upgrade To openSUSE 42.1 From openSUSE 13.2
Side-by-side: openSuSE Tumbleweed and Leap

 

 

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Posted by Mario1 - 27/12/2016 at 1:35 pm

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How to Recover Deleted Files in Linux

Deleted Files Recovery in Linux.

Deleted Files RecoveryAnybody might find himself/herself in  a situation where an important file has been accidentally deleted and, still worse, no valid backup copy can be found.

I noticed an interesting article in the Tecmint.com website (Linux HowTo’s Guide) that explains how you can recover deleted files in Linux and I have copied it below for your convenience.

How to Recover a Deleted File in Linux

Did this ever happen to you? You realized that you had mistakenly deleted a file – either through the Del key, or using rm in the command line.

In the first case, you can always go to the Trash, search for the file, and restore it to its original location. But what about the second case? As I am sure you probably know, the Linux command line does not send removed files anywhere – it REMOVES them. Bum. They’re gone.

Suggested Read: How to Recover Deleted Files/Directories Using Scalpel Tool

In this article we will share a tip that may be helpful to prevent this from happening to you, and a tool that you may consider using if at any point you are careless enough to do it anyway.

Create an alias to ‘rm -i’

The -i switch, when used with rm (and also other file-manipulation tools such as cp or mv) causes a prompt to appear before removing a file.

The same applies to copying, moving, or renaming a file in a location where one with the same name exists already.

This prompt gives you a second chance to consider if you actually want to remove the file – if you confirm the prompt, it will be gone. In that case, I’m sorry but this tip will not protect you from your own carelessness.

To replace rm with an alias to 'rm -i', do:

alias rm='rm -i'

The alias command will confirm that rm is now aliased:

Add Alias rm Command

Add Alias rm Command

However, this will only last during the current user session in the current shell. To make the change permanent, you will have to save it to ~/.bashrc (some distributions may use ~/.profile instead) as shown below:

Add Alias Permanently in Linux

Add Alias Permanently in Linux

In order for the changes in ~/.bashrc (or ~/.profile) to take effect immediately, source the file from the current shell:

. ~/.bashr

Active Alias in Linux

Active Alias in Linux

The forensics tool – Foremost

Hopefully, you will be careful with your files and will only need to use this tool while recovering a lost file from an external disk or USB drive.

However, if you realize you accidentally removed a file in your system and are going to panic – don’t. Let’s take a look at foremost, a forensics tool that was designed for this kind of scenarios.

To install foremost in CentOS/RHEL 7, you will need to enable Repoforge first:

# rpm -Uvh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm
# yum install foremost

Whereas in Debian and derivatives, just do

# aptitude install foremost

Once the installation has completed, let’s proceed with a simple test. We will begin by removing an image file named nosdos.jpg from the /boot/images directory:

# cd images
# rm nosdos.jpg

To recover it, use foremost as follows (you’ll need to identify the underlying partition first – /dev/sda1 is where /boot resides in this case):

# foremost -t jpg -i /dev/sda1 -o /home/gacanepa/rescued

where /home/gacanepa/rescued is a directory on a separate disk – keep in mind that recovering files on the same drive where the removed ones were located is not a wise move.

If, during the recovery, you occupy the same disk sectors where the removed files used to be, it may not be possible to recover anything. Additionally, it is essential to stop all your activities before performing the recovery.

After foremost has finished executing, the recovered file (if recovery was possible) will be found inside the /home/gacanepa/rescued/jpg directory.

Summary

In this article we have explained how to avoid removing a file accidentally and how to attempt to recover it if such an undesired event happens. Be warned, however, that foremost can take quite a while to run depending on the size of the partition.

 

References

10 Free Linux eBooks for Administrators

4 Free Shell Scripting eBooks

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Posted by Mario1 - 10/11/2016 at 1:19 pm

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How to Install Linux on a Windows Computer

How to install Linux.

Install LinuxMost people prefer to have both Linux and Windows, instead of replacing the Windows operating system and there are two main approaches to do that.

  1.  Dual-Booting
  2. Installing Linux in a Virtual Machine

I used the first approach in the past, but recently I found that having Linux in a Virtual Machine has some advantages, if you  need to access Windows applications without re-booting.

I found an interesting article www.makeuseof.com/ website with some good explanations on both alternatives and I have re-published it below for your convenience,

 

7 Reasons Why You Should (and Shouldn’t) Dual Boot Linux

by Moe Long

 

One of the most essential components of a computer is its operating system. The almighty OS is the lifeblood of a rig, determining software compatibility, and interacting with both hardware and software. For many, it’s either Linux vs. Windows or Linux vs. Mac.

Enter dual booting. How To Dual-Boot The Windows & Linux OS’s On Your Computer How To Dual-Boot The Windows & Linux OS’s On Your Computer It’s like having two computers in one – start your system up and choose between Windows and Linux. It’s called dual-booting, and it gives you access to two of the best operating systems on the… Read More

Essentially, this is having two operating systems available from boot. Windows has its pros, Linux has its pluses. Linux draws include its customization, security, dedicated open source community, and that distributions are (usually) free. Windows or Mac of course have their devout followers, and certain situations, like native apps and less complexity, call for a non-Linux distro.

But why not opt for both? Here are five reasons to dual boot and two reasons you shouldn’t.

Reasons You Should Dual Boot

Dual Boot Linux Windows
Image Credit: tmlee9 via Flickr

1. Gaming: Old and New

Play On Linux

Face it, there are pros and cons of both operating systems. Native gaming on Windows is better, while programming on Linux is much improved over Windows. Sure, thanks to Steam OS there’s been a push to optimize games for cross-compatibility. Such titles as Alien: Isolation and Half-Life 2 saw Linux versions alongside Windows and Mac iterations, and there are some fantastic gems hiding right there in the software center, but gaming is unarguably stronger on Windows.

Want to play those old games (think 16-bit)? Well, modern (64-bit) Windows architecture can’t handle them. Linux gracefully offers support of 16-bit programs via both 32- and 64-bit operating systems. Thanks to WINE, many Windows apps run like a champ. Want the best of gaming, both old and new? Dual boot. How to Play Retro Windows Games on Linux How to Play Retro Windows Games on Linux There’s something so satisfying about revisiting a retro PC game, like catching up with an old friend after many years apart. But how can you play classic Windows games on Linux? Read More

2. The Host

When running an operating system natively on a system (as opposed in a virtual machine, or VM), that operating system has full access to the host machine. Thus, dual booting means more access to hardware components, and in general it’s faster than utilizing a VM. Virtual machines typically are more system-intensive, so running Linux or Windows inside a VM requires pretty beefy specs for decent performance.

3. Compatibility

Netflix on Linux

You may find that many of your favorite programs don’t function quite as well in one operating system versus the other. Case in point: Netflix. There are several workarounds for streaming Netflix on Linux, but they do require a bit of tinkering. While most of us own some set-top box like a Roku, Apple TV, Chromecast, or game console, there are many situations (such as traveling) where you may only have your laptop. Having two operating systems installed ensures surefire access to all your programs and services. How to Watch Netflix Natively on Linux – the Easy Way How to Watch Netflix Natively on Linux – the Easy Way Using Netflix on Linux has been simplified considerably in the past few months. With the right browser, you can enjoy your favorite shows and movies from the popular streaming subscription service on your Linux device. Read More

4. Programming Is (Sometimes) Better on Linux

Want to get into programming? Linux has many advantages. It’s free, which is always a plus. Then there’s the bevy of languages including Java, PHP, Ruby, Perl, Python, and C/C++, loads of coding apps, and bash support. Oh, and knowledge of Linux looks fantastic on a resume. So familiarity with the ecosystem is in-demand.

Want to develop for Windows or Mac? Sure, you can totally use Linux, but it’s typically preferable to code apps for an operating system natively. Windows, for example, has the ultra-powerful Visual Studio and it’s the go-to for Windows apps. Consider dual booting for programming, and use Linux as a development environment.

5. It’s Really, Really Easy

There’s a misconception that Linux is ridiculously complex. Sure, the command line can be a bit daunting to the first-time user, and yes more tweaking is occasionally required when compared to using Windows or Mac. Ultimately Linux is merely an operating system, and may be used as simply that. How You Can Explain Linux to Anyone (So They’ll Get It) How You Can Explain Linux to Anyone (So They’ll Get It) How do you evangelize Linux to someone who doesn’t share your enthusiasm? How can you persuade your mom to switch from Windows? These tips will help you build an army of Linux newbies. Read More

Similarly, dual booting is a cinch. There are guidelines that ensure a smooth install. For instance, always make sure to install Linux second, after the primary operating system (failing to do so may result in problems booting). Sharing files is totally feasible as well, as Linux allows access to many Windows files.

Reasons You Shouldn’t Dual Boot

As with any installation scenario, there are some downsides that you should also consider.

1. Increased Complexity

While installation is not terribly difficult, sharing files across the two operating systems can be a challenge. Linux usually provides ease of access to Windows files, but accessing the Linux file system via Windows is a bit trickier. Linux mostly uses the EXT4 file system, and Windows requires a third party app for EXT4 compatibility. Although installation might be fairly simple, uninstalling can create a mess.

Overall, a dual boot set up is nowhere near as challenging as many tech tasks, but it will require a dash of patience and a side of ingenuity. If you’re not up to some mild troubleshooting, maybe skip the dual boot setup.

2. A VM Basically Accomplishes the Same Objective

Virtual Machine Linux
Image Credit: langkah-langkah via Flickr

As discussed earlier, a virtual machine is a great solution for running an operating system within an operating system. This method may be used to run Linux on a VM within another operating system, or vice versa. Plus, installation and uninstallation are pretty easy as it’s like removing a program and doesn’t affect anything with boot loaders.

Opting for the VM solution does take up more hard drive space, and resource allocation is much more than running just a Linux distro. Older hardware may not be suited to running a virtual machine, whether from lack of hard drive space or low system specs. Further, an operating system within a VM might not have full access to the host PC. When I first tried Ubuntu in a VM, I encountered problems using my DVD drive to install programs. Running Ubuntu natively on my hard drive (that is, installing it) alleviated this issue.

There’s no shortage of reasons to use Linux and Windows or Mac. Dual booting vs. a singular operating system each have their pros and cons, but ultimately dual booting is a wonderful solution that levels up compatibility, security, and functionality. Plus, it’s incredibly rewarding, especially for those making the foray into the Linux ecosystem

 

A Video on How to Install OpenSuSE Linux in the Oracle Virtual Box

References

Linux-13-1-installation-within-virtualbox/

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Posted by Mario1 - 10/10/2016 at 3:01 pm

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How to Make Firefox Run Faster

Make Firefox Run Faster.

I recently noticed an interesting article on the Field Guide website about ways to make Firefox run faster and I have re-published it below for your convenience

4 Easy Tricks to Make Firefox Run Faster

Mozilla Firefox was helping web users avoid Internet Explorer long before Google Chrome arrived, and it’s still going strong. Like all apps though, it can slow down over time. Here are four quick ways you can try to get the spring back in Firefox’s step.


1) Manage the cache

Firefox’s cache is designed to speed up your web browsing by storing certain files locally rather than having to fetch them every time. However, there’s a balance to be struck—if the cache gets too big then it can start causing problems and affect performance. Fortunately, Firefox includes some clever cache management options.

Choose Options from the Firefox menu, then click Advanced and Network. Here you can clear the cache (only do this occasionally) and decrease its size by ticking the Override automatic cache management box. If you have a lot of memory and drive space available, increasing the cache size could work better in terms of performance.


2) Refresh Firefox

Firefox has a built-in refresh feature that works a little like the refresh feature in Windows 10: it resets most of the browser’s settings without affecting any of your personal data, such as bookmarks, passwords, browsing history, cookies, and so on. It can often solve problems with sluggishness and the feature is handy for troubleshooting other issues as well.

Type “about:support” into the address bar in Firefox and then click the Refresh Firefox button to see if it makes a difference. You can also refresh the browser (and read more about the refresh feature) via this official guide. Some settings may need reconfiguring afterwards but you should notice a speed boost.


3) Cut down on the bloat

Dozens of redundant applications can slow down your computer, and dozens of redundant extensions and plug-ins can slow down Firefox. Getting rid of them not only means the browser becomes a leaner beast, it also improves browser security (as there are fewer bits of code to go wrong and fewer avenues through which hackers can get at you).

Choose Add-ons from the Firefox menu to disable both extensions and plug-ins. You may want to do a bit of research on the web before killing anything—particularly when it comes to plug-ins—to make sure you’re not going to break anything along the way. Plug-ins can only be deactivated, whereas you can either disable or remove extensions.


4) Install these two extensions

Yes, we just told you to uninstall most of your extensions, but some of them are genuinely useful. Take Auto Unload Tab, for example, which will ditch inactive tabs after a delay of your choice to free up memory and CPU resources. It’s pretty customizable too and you can specify particular tabs and URLs that you never want to be ‘unloaded.’

Then there’s Speed Tweaks—this extension gives you easy access to all those hidden Firefox flags that can speed up performance (they’re also accessible by visiting the “about:config” page). A quick web search on any of these flags will show you what they do and how you can tweak their associated values to improve your browser’s speed.

A Video on How to Speed Up Mozilla Firefox

References

How to Optimize Mozilla Firefox for Speed

How To View the HTML Source in Firefox

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Posted by Mario1 - 16/07/2016 at 10:40 am

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How to Create a Bootable USB Disk for Linux

Bootable USB Disk for Linux

A way to increase the security of your Linux installation is to create a Bootable USB Disk that can be used if you experience problems when you try to boot your Linux.

I found an interesting article on the Open Source Inside blog that provides a simple explanation on a way to do that by using the dd command and I have re-published it below for your convenience.

 

Create Bootable USB Disk For Linux With “dd” Command

Bootable USB Disk creation is one of the common thing that Linux users will do often in their Linux Life.. ?
There’s a several ways are available to create bootable USB Disk for Linux (such as UNetbootin, Linux live usb.. etc..).
“dd” command is one of the simple way to create bootable USB disk for Linux through Linux Command Line..and also, The most Linux distros comes with “dd” tool pre-installed.
Today i am going to show how to create bootable USB with “dd” command..

Note : dd is very powerful tool. dd stands for “Data Duplicator” which is make copy using block by block from one device into another device. So we can also use dd tool for data backup and restore from one device into another device. at the same time be careful wile using dd tool. because improper use may make your target device/memory stick unusable..

Now see how to create one with dd command….

The first thing you have to do is , identifying your USB device label.. it’s very important, Because if we identify it wrongly.. we will end up with data loss.. So be careful with while identifying which one is your intended USB disk for this operation.. Just see following example..

Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x000d5d58Device Boot Start End Blocks Id System
/dev/sda1 * 2048 52002815 26000384 83 Linux
/dev/sda2 52004862 312580095 130287617 5 Extended
Partition 2 does not start on physical sector boundary.
/dev/sda5 262002688 312580095 25288704 7 HPFS/NTFS/exFAT
/dev/sda6 52004864 60002303 3998720 82 Linux swap / Solaris
/dev/sda7 60004352 261988351 100992000 83 LinuxPartition table entries are not in disk order

Disk /dev/sdb: 15.6 GB, 15631122432 bytes
255 heads, 63 sectors/track, 1900 cylinders, total 30529536 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdb1
32 30529535 15264752 c W95 FAT32 (LBA)
shivaraj@shivaraj-A14RM0E:~$

 

Just note that… sdb is my pen drive/device (sdb1 is partition present in my pendrive /dev/sdb). That is assigned by Linux operating system automatically while inserting pen drive into our system. You can identify it by typing following command

sudo fdisk -l

After identifying our intended device to create bootable USB disk, we need to format our pen drive/device..
Before formatting the device/pen drive , we have to unmount all of its mounted partitions ..

So , unmount it first with following command..

sudo umount /dev/sdb1

Now format the pen drive to FAT32 disk format..

sudo mkfs.vfat -I /dev/sdb

The above command will format the pen drive and makes FAT filesystem.
After that use dd command to create bootable USB disk..

dd if=/path to iso/name_of_the_iso.iso of=/dev/sdb bs=1M; sync

For example, here i am going to create bootable USB disk from ubuntu-16.04-desktop-amd64.iso which is stored at ~/Downloads/os/.

dd if=~/Downloads/os/ubuntu-16.04-desktop-amd64.iso of=/dev/sdb

Here,
If stands for input file. It is used to specify the location of the ISO file.
Of stands for output file. It specifies where to write the ISO file. In our case, it’s /dev/sdb

It takes some time to copy one disk to another disk. dd tool does not show progressing status.

That’s all. You can use the same procedure to make any OS to make bootable USB drive.

Note that..While creating bootable USB by using above method, dd tool will make several partition on that pen drive. So after using bootable USB, It is best to format and use the pen drive for making another bootable ISO.

Don’t forget to unmount the USB … after unmounting the usb drive, run the following command to format it..

sudo mkfs.vfat -I /dev/sdb

That’s all for now… and guys, Don’t forget to share it with fellow Linux friends..

Happy Linux.. ?

 

A Video on How to Make Linux Bootable from USB

I found also a good video on this subject and you can watch it below:

References

Installing Linux onto a USB Flash Drive
How to Install Linux Alongside Windows with a USB
Create a Bootable Linux Flash Drive in Three Easy Steps

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Posted by Mario1 - 03/07/2016 at 11:37 am

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Disk Space Addition on Virtual Box

Virtual Box.

According to WikipediaOracle VM VirtualBox (formerly Sun VirtualBox, Sun xVM VirtualBox and Innotek VirtualBox) is a free and open-source hypervisor for x86 computers from Oracle Corporation. Developed initially by Innotek GmbH, it was acquired by Sun Microsystems in 2008 which was in turn acquired by Oracle in 2010.

VirtualBox may be installed on a number of host operating systems, including: Linux, OS X, Windows, Solaris, and OpenSolaris. There are also ports to FreeBSD and Genode.

It supports the creation and management of guest virtual machines running versions and derivations of Windows, Linux, BSD, OS/2, Solaris, Haiku, OSx86 and others,[6] and limited virtualization of OS X guests on Apple hardware”

I use Virtual Box on my laptop with Microsoft Windows to run also a separate Linux environment where I do most of my work.

When you install an Operating System under Virtual Box, you must specify a VirtualBox disk image that will be reserved to your new OS (emulated disk space for the Virtual Machine).

I found an interesting article on Through Out The Tunnel blog that explains how to add and extend disk space on Virtual Box  and I have re-published it below for your convenience,

Add and extend disk on Virtual Box through LVM

You can easily add and extend disk on Virtual Box through some LVM manipulations. LVM (Logical Volume Partitioning) is a device mapper target that provides logical volume management for the linux kernel. – Wikipedia. However, i have written a brief introduction about LVM on a previous post – Managing LVM with pvmove – Part 1.

Prior the extension is made you need to assure yourself there that you already  know the actual state of the machine’ s hard disk.

Those commands are helpful to perform your analysis before the operation is carried out.

>> fdisk -l

> pvdisplay >> vgdisplay >> lvdisplay

>> vgs >> lvs >> vgs

>> lsblk

 

Here is the state of the disk before the operation is carried out.

centos6

Now, you can get into your Oracle VM VirtualBox Manager to add the new disk.

The steps are :

  • Click on the ‘Settings’ option on the VirtualBox Manager after having selected your virtual machine which you intend to perform a disk extension. In my case its the ‘centos6’ one.
  • Then, on the ‘Storage’ option, next to the “Controller:SATA” there is an icon to “add new hard disk”.

Screenshot from 2015-10-16 07:25:41

  • Once you have click on the “add new hard disk” it will prompt you to “cancel” “choose existing disk” and “create new disk”. Choose “create new disk”. Of course, you can also choose an existing disk, but here we are adding a completely new fresh disk.
  • Afterwards, it will prompt a “create Virtual Hard Drive” box. Choose “VDI”. Click on next, then on “dynamically allocated”. Give a new name to your hard disk. In my case i am adding a new 2GB hard disk. Click on create and you are done.
  • Boot your machine if you are on VirtualBox, then fire the lsblk command to see your new hard disk. See screenshot below. You can also check with the fdisk -l command as well as the dmesg log which is really helpful.

centos6

  • Once the disk is detected, start by converting the disk to the PV using the command pvcreate /dev/sdb. You will notice that if you launch again a pvs the new disk is now on the PV but no part of the PV is allocated to any VG. As you can see on the picture below here is the new sdb which now forms part of the PV
  • Now we will extend the actual VG called vg_labo. Use the command vgextend vg_labo /dev/sdb

Screenshot from 2015-10-16 08:26:27

  • Once this is completed, you can now choose which LV you will extend. I am choosing the LV called lv_root. Use the command lvextend -l +100%FREE /dev/vg_labo/lv_root

Screenshot from 2015-10-16 08:34:42

The disk is now extended. You can also verify with the command df -h. You can also check out the following article on how to perform a pvmove.

Tips:

  • On Virtual Box, you cannot add a new disk if your machine is running compared to VMware. To be able to solve that issue, you will need to shutdown the machine to be able to add the disk.
  • If ever after adding a new hard disk, you noticed that the disk is not being detected just stay cool, as you might need to troubleshoot between LUNs on VCenter. Use the following command:

ls /sys/class/scsi_host/ | while read host ; do echo “- – -” > /sys/class/scsi_host/$host/scan ; done

  • You can also use the script rescanscsibus.sh after having install the sg3_utils package to troubleshoot for LUN detection.

A Video on Virtual Box

Refrences

The Beginner’s Guide to Creating Virtual Machines with VirtualBox

Managing LVM with pvmove – Part 1

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Posted by Mario1 - 04/04/2016 at 12:46 pm

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How to Convert a Linux Deb Package into an RPM Package

Convert Linux Deb to RPM.

If you work with Linux you know that different Linux distributions store their packages in different formats. For instance Debian and Ubuntu use deb packages, whereas OpenSuSE and others use rpm packages,

I recently noticed an interesting article on the http://tunnelix.com website that shows how to convert deb packages into rpm ones and I have re-published it below for your convenience.

Converting a Deb into RPM using Alien on OpenSuSE

Alien command is used by almost all system administrators. You might came across situations where you may need to install a .deb package on an OpenSUSE machine. You will need to convert it to a .rpm prior doing the installation. The alien command is simply a way to convert or install an alien binay package.

Photo credits: comicvine.com
Photo credits: comicvine.com

Installing Alien on OpenSUSE Leap

A general idea how to install a .deb package on an OpenSUSE by converting it to a .rpm file can be done with the command alien. If you have freshly install OpenSUSE Leap, you might noticed that command zypper install alien gives you the following error.

Screenshot from 2016-03-29 16-37-48

This can be solved easily as there is no repositories available. You can just jump on the Kamikaz Repo of the openSUSE factory. and fire the following commands :

zypper addrepo http://download.opensuse.org/repositories/home:KAMiKAZOW/openSUSE_Leap_42.1/home:KAMiKAZOW.repo
zypper refresh
zypper install alien

You  would have a result similar to this with all the dependencies installed.

Screenshot from 2016-03-29 16-43-42

You can finally launched the zypper install alien which will look similar to this.

Screenshot from 2016-03-29 16-44-24

Let’s now convert a .deb into a .rpm

I will take the example of the nmap tool. I have downloaded the nmap .deb file from the Ubuntu repo. You can choose your own deb file. This is the link to download the nmap from the Ubuntu repo.

wget http://mirrors.kernel.org/ubuntu/pool/main/n/nmap/nmap_7.01-2ubuntu1_amd64.deb

So to convert the file into a .rpm you need to launch the following command

alien --to-rpm <deb file name here>

Of course, on an openSUSE machine you would need the spec file. Here is an idea what kind of error you might came across.

Screenshot from 2016-03-29 16-56-07

Solving the error

The error “rpmbuild not found” clearly give a hint that the package rpmbuild is not found on the machine. Just install in with :

zypper install rpmbuild

Now that the rpmbuild package is installed with all the dependencies you can relaunch the command which in my case is

alien --to-rpm nmap_7.01-2ubuntu1_amd64.deb

A nice message message where the package.rpm is generated will be prompted. I have just taken the nmap package as a example. You can chose your own .deb file. Have funs with aliens.

 

A Video About Alien on Ubuntu to Install RPM Packages

 

 

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Posted by Mario1 - 01/04/2016 at 2:11 pm

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How to Convert a PDF file to a Doc Document

How to Edit a PDF file

PDF EditorsRecently I had to convert many PDF documents to a Doc format to be able to translate them from English to Italian.

I usually don’t do much editing work on PDF documents and therefore I never invested in a decent PDF editor. Moreover I am a proud Linux user and most of the PDF editors target the Windows environment,

I use LibreOffice on OpenSuse that allows to open PDF files, but manages them as graphic images that cannot be easily edited.

I decided therefore to look for a simple solution to convert the PDF files into documents with Microsoft Word format (.doc) that can be easily edited within LibreOffice. By the way LibreOffice allows to save a document in the PDF format if one wishes.

 

How to Convert a PDF file

I found an interesting free software called AbiWord that supports many different file formats, including also PDF documents.

According Wikipedia “AbiWord was originally started by SourceGear Corporation as the first part of a proposed AbiSuite but was adopted by open source developers after SourceGear changed its business focus and ceased development. It now runs on Linux, Microsoft Windows, ReactOS, Solaris, AmigaOS 4.0 (through its Cygnix X11 engine), MeeGo (on the Nokia N9 smartphone), Maemo (on the Nokia N810) QNX and other operating systems”.

The AbiWord user interface is pretty similar to that of Microsoft Words and you can easily access PDF documents and save them in a different formats such as awt, html. doc, docx, pdf, rtf, odt and many others.

I found therefore vary easy to convert PDF files by doing following simple steps:

  • Open in AbiWord the PDF file that you want to convert
  • Save the file as a Microsoft document with extension .doc or .docx
  • Edit the document, in my case translate it, either in AbiWord or with another document editor such as LibreOffice

 

How to Copy Images

When you open in AbiWord a PDF file that contains images, they are not imported in AbiWord.

I solved the problem with a copy paste operation from the PDF document to the edited document open in LibreOffice.

I use Okular to read PDF files and I had initially some difficulty to find a way to select an image and copy it.

I found that way to do it is as follows:

  • choose the selection tool from the Okular’s tools manu
  • select the area to be copied by moving the mouse over the area with the left button pressed
  • choose the copy option

After that you can just paste the image in the correct position of your target document.

 

An AbiWord Video Tutorial

 

References

5 cheaper alternatives to Acrobat for PDF editing

6 Best PDF Editors

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Posted by Mario1 - 10/03/2016 at 5:19 pm

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How to Create a PDF from HTML

From HTML to PDF

PDF ConverterRecently I have written a few courses on Cobol. and RPG for the IBM i (AS/400) by using one HTML document for each chapter. They were organised as a website where each chapter was accessible by clicking links.

I decided to distribute them as a simple PDF document that could easily by moved between machines and that could be read be when necessary in any place. I actually used directly the PDF document a few times to develop programs that used some of the techniques explained in the course. I could easily copy and paste some pieces of code from the PDF to my IBM i (AS/400).

I tried to use a few utilities available online to convert and combine the HTML files to a PDF e-book and I have written below some of my experiences.

 

Multiple HTML files to Single PDF with wkhtmltopdf

The utility called wkhtmltopdf has been developed originally for Linux but is available also on Windows,

The utility is well described in an article at http://explicate.blogspot.it where the author describes his experience as follows:

    • Made a list of the printable version URLs and saved the html files locally. (Not as tedious as it sounds, and mostly automated once the structure of the URLs was determined.)
    • Saved the pages locally with DownThemAll!
    • Used wkhtmltopdf to put the files together using a command similar to the following:   “C:\Program Files\wkhtmltopdf\wkhtmltopdf.exe” –footer-center [page] -s Letter articles.htm articles_001.htm articles_002.htm articles_003.htm articles_004.htm articles_005.htm articles_006.htm CoolRead.pdf”

I tried to install the utility on my Linux OpenSuSe 13.1 and on Windows 8. The installation succeeded but later I discovered the OpenSuSe version supported only the conversion of a single HTML file. The Windows version seemed to work correctly, but I found later that some of the links in the text did not point to the correct target.

 

HTML to PDF Conversion with HTMLDOC

HTMLDOC is a program for writing documentation in HTML and producing indexed HTML, PostScript, or PDF output (with tables of contents). It supports most HTML 3.2 and some HTML 4.0 syntax, as well as GIF, JPEG, and PNG images.

There is a good description of the utility in an article published on the Linux Blog.

There are different version of the program for different versions of Linux and also for Windows.

I downloaded the RPM version for OpenSuse 13.1 and after a simple installation I tried to use it with my HTML files.

The utility displays a window where you can enter the names of the HTML files and the name of the target PDF as in the following example:

HTMLDOC Utility

The form has different Tabs that contains options for the Input files, the Output formats, the optional Table of Contents (TOC), colors, fonts etc.

Once you have completed the form, you can generate the document by clicking on the Generate button of the HTMLDOC window.

When the conversion is completed you can open the PDF file that is produced by using Adobe Acrobat Reader or any other PDF viewing application.

I used the utility with my HTML files and found that the generated PDF document was satisfactory enough but it wasn’t perfect.

I had to remove all Copyright notices in the programs, because all program lines after the notice were not copied to the output, All links were correct, but they pointed to the end of the previous page instead of the beginning of the target page.

A Video on the Installation of HTMLDOC

A Video su wkhtmltopdf

Conclusions

Both utilities can produce PDF documents from HTML files, but I found the HTMLDOC easier to use (no need to type long command strings) and also able to generate better results.

I have seen on the web also other utilities, but i have tried to use only those described above.

 

References

HTMLDOC Users Manual
HTML to PDF – Convert HTML files to PDF
WkHtmlToPdf website
How to Learn RPG for the IBM i (AS/400)  – (An article on a PDF Course generated by using the HTMLDOC utility)
Edit PDF documents with LibreOffice Draw

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Posted by Mario1 - 23/03/2015 at 2:53 pm

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How to Learn RPG for the IBM i (AS/400)

How to Learn RPG

IBM iRPG is an old language that has been used recently especially on the IBM AS/400 eventually renamed as IBM i. It is not a widely known language today, but there are lots of applications written in RPG that require maintenance, support and enhancements.

Recently I read an interesting article on the IBM Systems Magazine with the title Who Knew RPGers Were So Important? that starts with the following considerations:

“Now we all like to think we are vital to the well-being of our companies, but according to CSC a shortage of RPG coders was partially responsible for a revenue shortfall of $230 million last year. Yes that’s “million.” While “only” $25 million to $40 million was specifically associated with the company’s RPG skills shortage, that still strikes us as a huge number. Hopefully upon reading that, all of CSC’s current RPG staff immediately demanded a pay raise. Clearly they are much more valuable than they had previously imagined!”

If you want to add RPG to your skills, you might consider purchasing one e-book that I wrote to present how RPG is used in a real application that I have developed in the past.

The IBM i CL and RPG Training by Example

 


Retail Value: 14.97 Euros



IBM i (AS/400/iSeries) CL and RPG ILE Training by Example
by Mario Pesce  

This e-book offers a progressive training on the IBM i (AS/400/ iSeries) CL and RPG languages. It uses a real life cross reference application to investigate how to use the latest ILE options and develop your skills..

It starts with simple programs and then examines more advanced concepts such as:

  • subfiles programming,
  • use of message subfiles,
  • use of embedded SQL,
  • development of ILE modules
  • binding modules into programs and service programs
  • CL utilities

 

The E-Book does not teach the basics of the language and is addressed to people who have already some RPG programming experience and want to learn more how to use all features of the RPG language.

If you want a complete overview of the language, I would advice to consider reading some good books such as the following available at Amazon:

 

 

A Video Course on RPG

I noticed on YouTube a video course on RPG and you can see below the first video

 

Conclusions

In the e-book I tried to write about some of the techniques that I have successfully used to develop well written and efficient RPG programs and I hope that they might be useful to other people interested in this language.

If you want to apply them and do not have an available IBM i (AS/400) machine, you might consider accessing some time sharing system that would allow you to use an IBM i accessed over the network for free or for a relatively small payment.

Some possibilities are the following:

==> PUB1.DE – Public AS/400

==> TimeShare 400

==> Rikas Communications

References

Steve Will on Finding RPG Programmers

RPG Academy: BIF UP Your Code! Get Rid of Those File Related Indicators

How to Learn RPG

How to Learn RPG by Scott Clement

RPG Programming I

RPG Academy: BIF Up Your Code! Get Rid of Those File-Related Indicators – See more at: http://www.mcpressonline.com/rpg/rpg-academy-bif-up-your-code-get-rid-of-those-file-related-indicators.html#sthash.oC9ySGIM.dpuf
RPG Academy: BIF Up Your Code! Get Rid of Those File-Related Indicators – See more at: http://www.mcpressonline.com/rpg/rpg-academy-bif-up-your-code-get-rid-of-those-file-related-indicators.html#sthash.oC9ySGIM.dpuf
RPG Academy: BIF Up Your Code! Get Rid of Those File-Related Indicators – See more at: http://www.mcpressonline.com/rpg/rpg-academy-bif-up-your-code-get-rid-of-those-file-related-indicators.html#sthash.oC9ySGIM.dpuf
RPG Academy: BIF Up Your Code! Get Rid of Those File-Related Indicators – See more at: http://www.mcpressonline.com/rpg/rpg-academy-bif-up-your-code-get-rid-of-those-file-related-indicators.html#sthash.oC9ySGIM.dpuf

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Posted by Mario1 - 11/03/2015 at 10:49 am

Categories: Ebooks, How to   Tags: