Perl one-liners: programs that get things done / by Peteris Krumins. pages cm. Summary: "Snappy Perl programs to streamline tasks and sharpen coding. the gnarly Perl one-liner for accomplishing short tasks that do not need a complete The -e switch allows me to write Perl scripts directly on the command line. ls -lAF | perl -e 'while () { print $_ }' total -rw-r--r-- 1 bfilipow bfilipow Oct 21 -rw-r--r-- 1 bfilipow bfilipow.

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Free Download Perl One-Liners: Programs That Get Things Done For any device Download here. Perl One-Liners showcases short and compelling lines of code that do all sorts of handy, geeky things. Chapter 1: Introduction to Perl One-Liners (PDF). Perl one-liners are small and awesome Perl programs that fit in a single line of code. They do one thing really well—like changing line spacing, numbering.

Take for example, this page.

I see an inefficient replacement of newline, instead of chomp. But since this is a one-liner, the "-l" option will do instead, and it will also save the output newlines.

I would say that this one-liner woult be better written as.

Apart from the dubious educational value of one-liners, I don't like this collection at all, for two reasons:. Since they are ready-to-use recipes, it would have been more useful to save each case into a well written Perl script, with properly named variables, and using a database when needed.

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Have you ever heard the expression "If you have a hammer, everything looks like a nail"? Or maybe in your case, "If you have a a dirty great big wrench , every nail, screw, thumb-tack and piece of blu-tac looks like it should be replaced with a dirty great big nut'n'bolt: Do you really import flat files into your DB for one-off column sums?

You must have an awful lot of once-used, ever-to-be-forgotten junk lying around in DB s. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco.

Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. So what if it's "cargo cult" or it occasionally doesn't have the very best way to do something?

Perl is sexy because the learning curve encourages diving in without really knowing what you're doing, then figuring stuff out later and getting "legit".

Scriptome encourages this approach. It presents a lot of useful info, in a compact way. I think it would be a better site if it allowed users to post improvements or observations at the bottom of "tools" pages, but even without this feedback feature, it looks pretty useful to me. So, thanks for posting the link. Even though I have been programming perl for over a year, I will be browsing this site for useful tricks I don't know yet.

You may see it by logging in. Back to Meditations.

Results 86 votes. Check out past polls. Comment on Scriptome and Perl One-Liners. Replies are listed 'Best First'. I am most likely to install a new module from CPAN if: PerlMonks graciously bestowed by Tim Vroom. PerlMonks was recently assimilated by The Perl Foundation. We don't bite newbies here Scriptome and Perl One-Liners by willyyam Priest.

The task scheduler is a key part of any operating system, and Linux continues to evolve and innovate in this area. In kernel 2.

Perl as a command line tool

This scheduler, instead of relying on run queues, uses a red-black tree implementation for task management. Explore the ideas…. As a Linux administrator, you may encounter rootfs errors like "cannot mount rootfs" and "kernel panic" when you try to reboot a server after attaching volumes from external storage or even after installing a new Linux operating system. This article outlines the Linux booting process on an x86 platform, shows….

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Linux system calls - we use them every day. But do you know how a system call is performed from user-space to the kernel?

Explore the Linux system call interface SCI , learn how to add new system calls and alternatives for doing so , and discover utilities related to the SCI. Neural nets may be the future of computing. A good way to understand them is with a puzzle that neural nets can be used to solve.

Now, construct a program that…. Scylla offers several key advantages over Cassandra such as scalability and better performance.

This article describes the…. Qlik Sense is a business intelligence tool that allows data to be discovered and visualized. Qlik Sense supports Hadoop environments as a data source. The Yocto Project is an open source project formed with the goal of making embedded Linux development easier and more portable across architectures. This article introduces the project and provides a step-by-step walk through on how to get started.

Python 2. The construct is generators; the keyword is yield. Generators make possible several new, powerful, and expressive programming idioms, but are also a little bit hard to get one's mind around at first glance. In this article, David provides a…. Porting from Linux on x86 to Linux on Power is usually easy, but developers should be aware of differences that may manifest as compilation, linking, or run-time errors, or performance issues.

This article lists those differences, and describes approaches for fixing, improving, or working around them. Awareness of these differences…. Learning how to use the API for OpenSSL -- the best-known open library for secure communication -- can be intimidating, because the documentation is incomplete. Fill in the gaps, and tame the API, with the tips in this article. After setting up a basic connection, see how to use OpenSSL's….

Although users usually think of Python as a procedural and object-oriented language, it actually contains everything you need for a completely functional approach to programming.

This article discusses general concepts of functional programming, and illustrates ways of implementing functional techniques in Python. The article also describes how to protect data on internal disks in an enterprise deployment and achieve high availability and uninterrupted service. This article describes the changes to the IBM Power Architecture that can be used to provide enhanced protection of virtual machines from other software running on the same system.

A new higher privilege mode called Ultravisor mode is being introduced, along with the concept of secure virtual machines SVMs. In Part 4 of this series, you'll learn how to extend the Spigot server with a plugin that uses Watson cognitive services to add a little science to your game play.

More Perl One-liners

Use the material in this tutorial to study for the LPI exam for Linux system administrator certification or to learn for fun. It also describes the differences in the performance of tuned daemon profiles in the two operating systems. Back to top. Linux Microservices Mobile Node. Skip to content. The open source operating system that runs the world. What's Trending Tutorial Learn Linux, A roadmap for LPIC Tutorial Learn Linux, Fundamentals of internet protocols.

Tutorial Five pitfalls of Linux sockets programming.In this case it should be converted into a regular script. Their ping statuses are captured as events and are notified as email, SMS, and slack…. These one-liners are followed by a section that demonstrates how to convert a one liner into a full Perl script.

Scripting Languages: Beware Perl authors who prefer the second variant to the first ;-.