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Jerry Peek Archive

Jerry Peek is a freelance writer and instructor who has used Unix and Linux for more than 25 years. He's happy to hear from readers; see http://www.jpeek.com/contact.html.
There’s a Lot in the Dot: Filesystem Permissions and Pathnames (Part 2)
Still deeper into the dot (.) with an dive into access permissions. Study up because there's going to be a quiz.
There’s a Lot in the Dot: Filesystem Permissions and Pathnames (Part 1)
Beginning with a brief tour of the filesystem, we take you deep into the dot (.) of your directory listing so you can get the most from your CLI.
Power Up Linux GUI Apps
Save time and gain functionality by starting your GUI apps from the command line.
Slicing and Dicing on the Command Line
If you don't know text, you don't know Linux. There are a host of methods for reformatting plain text -- including the text used by graphical applications like spreadsheets and email programs.
Linux Runs on Text: Understanding & Handling Text
Text plays a central role in the Linux operating system. Take better control of your system with a firm understanding of what text is and how best to handle, format and convert it.
Power Tools: Piles of Files
Using text and utilities to organize and access files.
Filenames by Design, Part Two
Continuing our series on how to take full advantage of your filesystem with tips and tricks for the newbie and old pro alike.
What’s the diff?
Get more control over how file differences are found and displayed with some lesser-known options, and other techniques for getting the output you need.
Filenames by Design, Part One
Learn to take full advantage of your filesystem with tips and tricks for the newbie and old pro alike.
The Importance of Command Line Literacy
The oldest interface is still one of the best. Learning about shells and utilities can pay off for jobs where they're the fastest or most flexible.
Wizard Boot Camp, Part 10: Utilities You Should Know
The time has come to leave Hogwarts, young wizard! We wrap up our ten-part series on becoming a command-line wizard with a look at more utilities you should know.
What’s GNU, Part Four: find
Since find(1) came into being decades ago, programmers have been adding new features. Here's the fourth of a series about some of those.
Wizard Boot Camp, Part Nine: (More) Utilities You Should Know
We're starting to wrap things up with the Wizard series. This time around we expand on the utilities that should be at your fingertips.
Wizard Boot Camp, Part Eight: Utilities You Should Know
Before you reach for that scripting language, make sure you're making the most of the shell utilities that you have at your fingertips!
Wizard Boot Camp, Part Seven: /proc Process-Info
Digging into the dark corners of /proc pseudo-filesystem to wrap up our discussion of Linux processes.
Wizard Boot Camp, Part Six: Daemons & Subshells
More about processes and signals: writing daemons, suspending subshells.
Wizard Boot Camp, Part Five: Control Processes Using Signals
A true wizard doesn't just run processes, a true wizard knows how to communicate with those processes through signals to stop, restart, and even kill processes. This may sound like arcane and obscure knowledge, but if you follow along, you'll be managing your processes like an adept in no time.
Wizard Boot Camp, Part Four: Tracking Processes
You probably already know you can examine process status with ps, but most users never embrace the full power of this great little utility.
Wizard Boot Camp, Part Three: Using Standard I/O from Shells
Last month's column, the second in this series of obscure Linux features that wizards should know, introduced Standard I/O. This month we'll see how to take advantage of Standard I/O from a shell-- including an example using named pipes (FIFOs).
Wizard Boot Camp, Part Two: Intro to Standard I/O
In the second installment of the "Boot Camp for Wizards" series, Jerry Peek continues with a discussion of the standard I/O system.
Doing More with less, Part Two
You probably use less all the time, but do you use all its power? Jerry Peek shows you how to get the most out of less in the second part of his look at the less utility.
Doing More with less, part one
Developer Mark Nudelman has been working on less since version less-1, released in 1985. This month, let's cover the Linux version less-394 (yes, it's the 394th version), but you can also get less for other operating systems, including Mac OS X and Microsoft Windows — which makes it a great cross-platform choice for exploring files and viewing data from pipes.
Merging and More with diff3
Learn how to use diff3 to compare and merge files.
Bits and pieces: Comparing Binary Data (and More)
If a standard Linux utility doesn't do quite what you want, adapt it.
Cygwin, Part Three
Cygwin utilities let you do what Windows programs don’t.
Wizard Boot Camp, Part One: Linux, Shells & Commands
Here's the start of a series on little-known topics that wizards should know. Knowledge of the Harry Potter series not required.
sdiff and More
More on GNU diffutils. A look into sdiff, which shows file comparisons side-by-side and lets you merge two files interactively.
Cygwin, Part Two: Linux-like Shells
Your favorite Linux shell — bash, zsh, ksh, and more — is probably part of the Cygwin package.
A Better Windows Command-Line
Linux gurus who also use Microsoft Windows can have Linux-like command-line tools to make life easier and less confusing.
The Joy of Vim, Part Three
Take a look at a few of the powerful new features that make vim Vi IMproved: a visual text-selection mode, moving the cursor to places without text (yet), incrementing and decrementing numbers, storing editing commands in registers, handling binary files and different end-of-line styles, line breaking, and screen scrolling.
Why Use vim?, Part Two
Dig into some of vim’s programmable features: improvements in key mapping, a scripting language, and built-in and user-defined functions.
The Joy of Vim, Part One
>Here’s the first in a series about how vim (“ vi improved”) is improved.
The Joy of Vim, Part One
Here’s the first in a series about how vim (“ vi improved”) is improved.
ImageMagick, Part Two
More about a sophisticated package of tools for creating and editing high-quality images.
ImageMagick, Part Three
The last of a three-part series on tools for creating and editing high-quality images.
ImageMagick, Part One
ImageMagick is a package of tools for creating and editing images that’s not easy to get started with, but is well worth the effort. Here’s an introduction, just in time for processing those summer photos.
Semi-Automated Editing
When it’s just too hard to automate text conversion, try adding some human judgement using editing macros.
ImageMagick, Part 1
ImageMagick is a package of tools for creating and editing images that’s not easy to get started with, but is well worth the effort. Here’s an introduction, just in time for processing those summer photos.
What’s GNU in Old Utilities, Part Seven
Here’s the last in a series about new features of perennial utilities. This time: date, wc, du, and more.
What’s GNU in Old Utilities: tar
What’s new with tar since it was written eons ago? A lot. Here’s the sixth of a series about new features of old utilities.
What’s GNU in Old Utilities, Part Six: tar
What’s new with tar since it was written eons ago? A lot. Here’s the sixth of a series about new features of old utilities.
What’s GNU in Old Utilities, Part Five: sort
For decades, sort has been extended over and over again to make it more and more useful. Here’s the fifth in an ongoing series about new features in familiar utilities.
What’s GNU in Old Utilities: sort
For decades, sort has been extended over and over again to make it more and more useful. Here’s the fifth in an ongoing series about new features in familiar utilities.
New Shells, Part Three: Fish
The Friendly Interactive Shell, or fish, is" friendly" because it’s easier to use, not because it’s" dumbed down."
What’s GNU in Old Utilities, Part Three
Utility programs like cp have new features you may not have seen. Here’s the third in a series about some of the handiest.
What’s GNU in Old Utilities, Part Two
Utility programs like grep have new features that you may not have seen. Here’s the second of a series of articles about some of the handiest.
New Shells, Part Two: vshnu
vshnu is a “visual shell” that runs in a terminal window, combining navigation shortcuts with a standard shell and the power of Perl.
New Shells: Zoibderg
bash, tcsh, zsh, and their kin are all subspecies of the same beast. In search of something novel, let’s look at the first of a number of different breeds: Zoidberg.
On the Trail of the Z Shell
Whether you're new to Linux or longtime Penguinista, a powerful command-line shell can boost productivity. From helpful prompts, to automatic argument completion, to time-saving command-line editing, there are many features to enjoy in modern shells. One of the most modern is the Z Shell, or zsh.
New Shells, Part One: Zoidberg
bash, tcsh, zsh, and their kin are all subspecies of the same beast. This month, let’s look at the first of a number of different breeds: a Perl shell, Zoidberg.
Instant Environment Variable
If you use bash, you can set an environment variable for a single command by setting the variable before the command, like this: VISUAL=/usr/bin/emacs ci -l foo.txt
What’s GNU in Old Utilities, Part One
Utility programs like ls have new features that you may not have seen. This is the first in a series about some of the handiest enhancements.
Filename Trouble
Spaces in filenames can cause some pesky problems. But there are workarounds.
More Data Surgery
Got text data? Linux has a variety of tools to format, process, and print it.
The Unknown Power Tool: m4, Part Two
Dig deeper into m4, and look at included files, diversions, frozen files, and debugging and tracing.
It’s (Not) Magic
Learn the practical magic of magic numbers.
On the T(r)ail of Open Files
Learn how Linux manages open files and explore a number of utilities to watch files as they grow.
gFTP and More
Linux often gives you lots of ways to do the same thing and file transfer is no exception. We covered file transfer in three columns from March to May 2003 (available online at http://www.linux-mag.com/depts/power.html). This month let's look at yet another variation using gFTP and some not-so-obvious details that can help you navigate all of the file transfer protocols.
Performing Data Surgery
A year ago, the November 2003 "Power Tools" column (available online at http://www.linux-mag.com/2003-11/power_01.html) looked into some lesser-known tools for editing text: the line editors ex and ed, and the stream editor sed.
Think Links
Why would you want to give a program more than one name? How can you move quickly through the filesystem like Star Trek's Enterprise jumping through a "worm hole"? What good are multiple views of the files in a directory? You'll see these things and more, as we look into Linux filesystem links.
Fix Images Fast with Netpbm
Imagine that:
Execution and Redirection
While the title of this month's "Power Tools" is "Execution and Redirection," it's not about about dying and going to heaven. Instead, controlling execution and redirecting input and output is an important part of managing Linux processes.
Great Command-line Combinations
Tools with graphical user interfaces (GUIs) can be easy to learn. All of their commands and options are typically laid out on menus and dialog boxes, making it easy to discover what the tool can do. If "easy" and "intuitive" are your main criteria for programs, then a GUI tool may always be the right choice.
Personal Version Control
If you've worked with a group of programmers, you've probably used version control software like CVS. However, version control is also useful for non-programmers -- for instance, for a group of technical writers producing product documentation.
Wilder Wildcards
In last December's column, "Wildcards Gone... Wild" (available online at http://www.linux-mag.com/id/1528/), we looked at ways to match groups of files in a hurry, with a minimum of typing, by using shell wildcards. Last month, we saw some of the wilder things that the Z shell, zsh, can do to make computing easier. This month we'll mix those two topics and look at some of the most powerful zsh wildcards and similar, related features in other shells.
Catching some ZZZs
Linux systems have several shells available -- some more powerful than others. Perhaps the most powerful shell is zsh, the Z shell. To give you an idea of the shell's size and complexity, the zshall man page in plain-text format weighs in at more than 16,000 lines. (Rest easy. We won't try to cover all of zsh in this month's column.)
Cross-platform command lines
In an editorial a few months ago, Editor-in-Chief Martin Streicher pointed out that, whether we like Microsoft or not, it's a fact that many of us use Windows systems. Some of us use Macintosh computers with OS X. Each of those systems has a different graphical interface. Yes, you can install the X Window System on Macs and PCs, but wouldn't it be great to have the same standard interface to all of those systems, right out of the box?
Wildcards Gone Wild
When you type a filename on the command line (at a shell prompt), you may use filename completion to save time and typing. A popular feature, filename completion lets you type the first few letters of a file or directory name and use the TAB key to ask the shell to fill in the rest.
(Very) Small Editors
Linux systems use text pervasively and provide an almost- infinite number of tools to manipulate it. This month, let's look at three lesser-known text handling tools: the line editors ex (which is usually part of the vi editor) and ed, and the stream editor, sed.
Email Control
For a lot of us these days, "control" of email is more of a sad joke than a reality. New laws may not do much to stop the flood of spam, and viruses and worms keep sneaking in. As incoming messages make your server struggle and users' inboxes groan, what's an administrator -- or a user -- to do?
(Not So) Stupid Shell Tricks
Graphical environments have lots of fun add-ons, such as skins, themes, and more. If you use a terminal or other shell-based applications, it's enough to make you feel left out. This month's "Power Tools" column aims to change that.
Pure Postal Power
Last month's feature, "Personal Post," (available online at http://www.linux-mag.com/2003-07/email_01.html) explained how email is delivered, and also described a variety of power tools ideal for untangling a morass of messages.
Personal Post
Overwhelmed by email? Or is your setup okay? We'll bet you can do better. Here are some power tools to turn your post from a pain to a pleasure.
screen: Windows that Follow You
How can you start a job from one system and finish it on another? For example:
Transfer Tips, Part III
This month, we'll take our third and final look at transferring files between systems. The utilities we'll check out this month, rsync and unison, analyze two sets of files and synchronize them, making the two sets identical with little or no help from you. Given a source and a destination, rsync makes all destination files match those at the source. unison works in both directions, automatically making any changes that don't conflict and asking you about the rest.
Transfer Tips, Part II
Last month's column (available online at http://www.linux-mag.com/2003-03/power_01.html) presented a number of ways to transfer files by hand with ssh and scp and the power of the shell. This month's column looks at ways to transfer and synchronize sets of files automatically with ftp, sftp, and wget. Along the way, you'll also see tips on compressed ssh and detached processes. Let's dig in!
Transfer Tips, Part I
You're in Cape Town, but your data is in California. You're using a Sun system in your office, but your bleeding-edge Mozilla browser with the very cool theme and all of your favorite bookmarks is on your Linux box at home. How can you get bits from there to here without being there?
Running Jobs Unattended
Linux systems have several ways to run jobs unattended at some later time -- either once or many times. Scheduling jobs in the future is handy for system maintenance, for sending yourself reminders, and for making more practical and efficient use of your CPU by running jobs when users are away.
Inside the Lizard’s Lair
After a development cycle that seemed like an eternity -- during which Internet Explorer supposedly "won" the "browser war" -- Mozilla, the open source application suite that's also the basis for Netscape, has become a stable and capable package with a new codebase. With Mozilla, you can browse the Web, read email and newsgroups, chat, and more. If you use multiple platforms, Mozilla is an ideal client: you can have the same, familiar Mozilla features and user interface on every machine you use (including Macintosh, Windows, Linux, Unix, just to name a few).
Using Power Wisely
One Linux user is special: the superuser or root. If you manage any number of Linux boxes -- even just your own desktop workstation -- you'll inevitably need root access to configure or tune the system or manage system resources. But with great wizardly powers also come risks. This month, let's see how to manage root access and learn some powerful tricks to juggle Linux processes and shells.
What’s in a Pathname?
How can you locate something in the filesystem with the least amount of work? You might be tempted to use a graphical (GUI) file manager, but in many cases the command line is faster. If you do a lot of work with your system, learning some pathname power tools can save you a lot of time.
A Very Valuable Find
Unless you're superbly organized or have a great memory, chances are you "misplace" files from time to time. Find answers the question, "Now, where did I put that?"