Like interrupts, some devices have a fixed DMA channel. Most processes consist of only a single thread; they are called single-threaded. The data is read by a head, which can detect whether a particular minute particle is magnetized. On GNU/Linux systems a file command can be used to identify …

Python has always touted itself as a "batteries included" language; its standard library contains lots of useful modules, often more than enough to solve many types of problems quickly. To understand what OSS is, you must first understand how source code is used to create programs. In all cases, bash …

Its latest releases often inspire the other Linux distributions to adopt new features and make changes. Just as IP packets have their own header, TCP has its own header. This integration would result in efficient administration. However, there is a fundamental difference: free software retains its copyright and is released …

Students should, at least, be given the opportunity to see how their new tools work. If a blocked signal is generated, it remains pending until it is unblocked. It's basically community version of Red Hat without any fee or support. The BSD socket layer passes the socket data structure representing …

There are various other shell interpreters available, such as Korn shell, C shell and more. The first method is most often the easiest, as long as your system UEFI boot manager allows you to disable the secure boot feature. For the operating system to accomplish this, it must contain the …

For those companies, Linux supports most UNIX commands and standards, which makes transitioning to Linux very easy because the company likely would not need to pur- chase additional software or retrain staff. Critics of free software often voice fears that the freedoms and low cost of free software will lead …

In the Linux world, a large number of users will always prefer to compile applications from source, rather than using an installer package. While there are other options, the most common scripting language is Bash. It's a must try Linux distribution for those are willing to test the working of …

Linux is full of shortcuts to help make your life easier. Those programs or issues that have not yet been addressed or resolved for Linux can still reside on the original drive and remain operational as long as they are needed. Free software, as the term is usually used, and …

There are three types of partition supported by fdisk, primary, extended and logical. The examples continue, but all hit the same chord: there is no use in preventing the spread of information. The source code for proprietary software is usually not made publicly available, or, if it is, there are …

Sed is the Spanish word for thirst, Though you may thirst (or hunger, or whatever) for an easier way to do things, its name did not derive from there. As of April 2008, Linux had fewer than 100 known viruses, whereas Windows had more than 1,000,000 known viruses …

The LSB is a joint project of several Linux vendors under the auspices of the Linux Foundation (formerly the Free Standards Group). A filesystem is a collection of files and directories in a formal and valid hierarchy. Commercial programming packages, like commercial operating systems, can cost a great deal of …

We have icons too, you know. An API defines the interfaces by which one piece of software communicates with another at the source level. These processes range from things like the X Window System to system programs (daemons) that are started when the computer boots. A runnable process is one …

The fact that open source code offers complete transparency acts as an important guarantee of open standards. Constraining students to move the mouse within the confines of the instruction set of a few closed, proprietary programs merely cages those students and constrains our future. Unlike character devices, there are classes …

The IP protocol is a transport layer that is used by other protocols to carry their data. One interesting feature it has is that every instruction is conditional. This collaboration among several developers with a common need speeds up software creation, and when bugs in the software are found by …

The IP protocol layer itself uses many different physical media to transport IP packets to other IP hosts. If you look at the output of lsmod, you will see that each module has a count associated with it. Until recently, most modems were 8 or 16 bit ISA cards. While …

The first, the old timer mechanism, has a static array of 32 pointers to timer_struct data structures and a mask of active timers, timer_active. Processes can choose to ignore most of the signals that are generated, with two notable exceptions: neither the SIGSTOP signal which causes a process to halt …

It links the sock data structure to the BSD socket data structure using the data pointer in the BSD socket. The GNU C library provides more than its name suggests. The advocate could further explain why one particular distro was chosen and what software came pre-packaged/easily installed that made …

Because Linux has such a large number of contributors from across multiple decades of development, contacting each individual author and getting them to agree to a new license is virtually impossible, so that Linux remaining licensed under the GPLv2 in perpetuity is all but assured. They prefer the term open …

Open Source software, like its name suggests, provides users with an open code that can be freely used, modified, and shared by everyone. The so-called open source and free software development models started with the Free Software Foundation and were popularized with Linux. Each filesystem is mounted to a specific …

If you find a bug, report it! The format most common in Linux is called Executable and Linkable Format (ELF). But all things come to an end eventually. You would want that file access to be strictly coordinated.

How much do you know about the Linux rlogin command?

You can pick up a book on Unix from the '80s and much of it will still be applicable to a modern Linux distribution today. Linux provides any tools you need as a developer to operate a scalable, secure servers. When TCP transmits its packet using IP, the data contained …

Libraries were written and ported, filesystems developed, and hardware drivers written for many popular devices. An exit status of zero indicates success. Tied closely to IoT is the drone trend, that of remotely controlled flying robots. A character device is accessed as a linear queue of bytes.

Shortcuts for nameif …

That is, they do not require that the source code be included with redistributions of modified versions of programs that use such licenses. Also, the lack of a common kernel within Unix distributions has implications for software and hardware vendors. Software is not some mystic magic which must be locked …

Most of the malware are propagated through the Internet. You might also wonder whether ext4 is still in active development at all, given the flurries of news coverage of alternate filesystems such as btrfs, xfs, and zfs. It is sad to see that people today actually have to use the …

The GPL subsequently became by far the most widely used license for free software. Currently, in Distrowatch's past 6 months ranking, it sits at #3. Linux is a topic which is equally suitable for study in the classroom (such as at a university or a specialized computer school) or at …

Specific filesystems, however, may impose their own restrictions, imposing a smaller ceiling on the maximum length. It is not possible to directly link user-space applications with kernel space. In many ways, Linux and UNIX administration is today much easier than administration for popular commercial personal operating systems because it is …

Linux protects against this by maintaining lists of adjustments to the semaphore arrays. There are three types of partition supported by fdisk, primary, extended and logical. The first filesystem mounted is located in the root of the namespace, /, and is called the root filesystem. It doesn't take long to realize …

Most recently, the U.S. Whereas it had previously been the norm to assist colleagues and freely share ideas and software, such cooperation suddenly became forbidden and was made a crime. But this book, like most texts on system programming, is unconcerned with kernel development. Linux is a popular platform …

Keep in mind that these are only conventions---not rules. You can easily see the exported kernel symbols and their values by looking at /proc/ksyms or by using the ksyms utility. Traditionally, Unix programs have been single-threaded, owing to Unix's historic simplicity, fast process creation times, and robust IPC mechanisms …

After moving the Linux I've noticed a dramatic improvement in the speed and performance of my work flow, with the exact same tools I used on Windows. What does this mean to you? Each individual semaphore operation may request that an adjustment be maintained. The Free Software Movement would be …

Without this surrounding commitment, IT decision-makers can be left in the dark...and that's not a good place to be in 2019. Device drivers have to be careful when using memory. The character % introduces a job name. Writing a byte to a file position beyond the end of the file …

The world economy will not collapse if creators of software choose to share their work with the world. When adding a user to a system you will be asked for your root i.d. In all of the cases above, the synergy created between the pairs has only gone to …

It is as old as computers themselves. As the information age went on, though, corporations became progressively more obsessed with controlling the spread of knowledge. The boom in interest around the Internet of Things (IoT), the notion of a network of devices, big and small, that can "talk" to each …

By contrast, most software carries fine print that denies users these basic rights, leaving them susceptible to the whims of its owners and vulnerable to surveillance. There is no problem with using an older computer, for example, an elderly 500MHz Pentium PC with as few as five gigabytes of hard …

A server is a computer with an operating system that is configured to allow other computers to connect to it from across a network. This is one of those arguments that sounds good superficially but which is not borne out by the evidence. If you plan to incorporate such software …

Physical filesystems reside on block storage devices, such as CDs, floppy disks, compact flash cards, or hard drives. Today open source software has become critical for almost every organization. If you love the rolling Linux distributions (here are some fixed vs rolling release differences), then you don't need to look …

Each device driver tells the operating system how to use that specific device. The process tree is rooted at the first process, known as the init process, which is typically the init program. By and throughout the 1990s, you could find MINIX installations thriving in universities worldwide-and a young Linus …

No distribution of Linux is completely bug-free, so you may be required to fix small problems by hand after installation. Keep in mind that these are only conventions---not rules. There are Web sites, articles, and books devoted to the subject, and Linux User Groups (also known as LUGs) meet in …

From the filename, the kernel obtains the inode number. The command cd may be run without a location as we saw in the shortcut above but usually will be run with a single command line argument which is the location we would like to change into. A block device cannot …

Initially, there is only one directory on the disk, the root directory. But note that this book does not cover the Linux programming environment -for example, there is no tutorial on make in these pages. The count is the number of kernel entities that are dependent on this module. In …