Command Line Interface Quotes

Why can't you summon a command line and search your real-world home for 'Honda car keys,' and specify rooms in your house to search instead of folders or paths in your computer's home directory? It's a crippling design flaw in the real-world interface.

What would the engineer say, after you had explained your problem and enumerated all of the dissastisfactions in your life? He would probably tell you that life is a very hard and complicated thing; that no interface can change that; that anyone who believes otherwise is a sucker; and that if you don’t like having choices made for you, you should start making your own.

graphical user interfaces make easy tasks easy, while command line interfaces make difficult tasks possible

Disney and Apple/Microsoft are in the same business: short-circuiting laborious, explicit verbal communication with expensively designed interfaces. Disney is a sort of user interface unto itself—and more than just graphical. Let’s call it a Sensorial Interface. It can be applied to anything in the world, real or imagined, albeit at staggering expense.

think that the message is very clear here: somewhere outside of and beyond our universe is an operating system, coded up over incalculable spans of time by some kind of hacker-demiurge. The cosmic operating system uses a command line interface. It runs on something like a teletype, with lots of noise and heat; punched-out bits flutter down into its hopper like drifting stars. The demiurge sits at his teletype, pounding out one command line after another, specifying the values of fundamental constants of physics: universe -G 6.672e-11 -e 1.602e-19 -h 6.626e-34 -protonmass 1.673e-27…. and when he’s finished typing out the command line, his right pinky hesitates above the enter key for an aeon or two, wondering what’s going to happen; then down it comes—and the whack you hear is another Big Bang.

strongest reasons early adopters of Linux chose it over, say, Windows NT was the powerful command line interface which made the “difficult tasks possible.” What This Book Is About This book is a broad overview of “living” on the Linux command line. Unlike some books that concentrate on just a single program, such as the shell program, bash, this book will try to convey how to get along with the command line interface in a larger sense. How does it all work? What can it do? What's the best way to use it? This is not a book about Linux system administration. While any serious discussion of the command line will invariably lead to system administration topics, this book only touches on a few administration issues. It will, however, prepare the reader for additional study by providing a solid foundation in the use of the command line, an essential tool for any serious system administration task. This book is very Linux-centric. Many other books try to broaden their appeal by including other platforms such as generic Unix and OS X. In doing so, they “water down” their content to feature only general topics. This book, on the other hand, only covers contemporary Linux distributions. Ninety-five percent of the content is useful for users of other Unix-like systems, but this book is highly

As I’ve explained, selling OSes for money is a basically untenable position, and the only way Apple and Microsoft can get away with it is by pursuing technological advancements as aggressively as they can, and by getting people to believe in, and to pay for, a particular image: in the case of Apple, that of the creative free thinker, and in the case of Microsoft, that of the respectable techno-bourgeois. Just like Disney, they’re making money from selling an interface, a magic mirror. It has to be polished and seamless, or else the whole illusion is ruined and the business plan vanishes like a mirage.

What would the engineer say, after you had explained your problem and enumerated all of the dissatisfactions in your life? He would probably tell you that life is a very hard and complicated thing; that no interface can change that; that anyone who believes otherwise is a sucker; and that if you don’t like having choices made for you, you should start making your own.

When Ronald Reagan was a radio announcer, he used to call baseball games that he did not physically attend by reading the terse descriptions that trickled in over the telegraph wire and were printed out on a paper tape. He would sit there, all by himself in a padded room with a microphone, and the paper tape would creep out of the machine and crawl over the palm of his hand printed with cryptic abbreviations. If the count went to three and two, Reagan would describe the scene as he saw it in his mind’s eye: “The brawny left-hander steps out of the batter’s box to wipe the sweat from his brow. The umpire steps forward to sweep the dirt from home plate,” and so on. When the cryptogram on the paper tape announced a base hit, he would whack the edge of the table with a pencil, creating a little sound effect, and describe the arc of the ball as if he could actually see it. His listeners, many of whom presumably thought that Reagan was actually at the ballpark watching the game, would reconstruct the scene in their minds according to his descriptions. This is exactly how the World Wide Web works: the HTML files are the pithy description on the paper tape, and your web browser is Ronald Reagan. The same is true of graphical user interfaces in general.

Image Assistant command line interface (CLI) operations. For more information, see Create Your AppStream 2.0 Image Programmatically by Using the Image Assistant CLI Operations.

The other, somewhat subtler point, was that interface is very important. Sure, the MGB was a lousy car in almost every way that counted: balky, unreliable, underpowered. But it was fun to drive. It was responsive. Every pebble on the road was felt in the bones, every nuance in the pavement transmitted instantly to the driver's hands. He could listen to the engine and tell what was wrong with it. The steering responded immediately to commands from his hands. To us passengers it was a pointless exercise in going nowhere--about as interesting as peering over someone's shoulder while he punches numbers into a spreadsheet. But to the driver it was an experience. For a short time he was extending his body and his senses into a larger realm, and doing things that he couldn't do unassisted.

It is perhaps worth pointing out what criteria are not required in ordered to be considered lean in Eric Ries’ context: Bootstrapped Consuming unholy amounts of Top Ramen on a daily basis Unpaid workers Build system based on a 386 architecture Open cubicle culture Command-line interface Chairs without casters

Why are we rejecting explicit word-based interfaces, and embracing graphical or sensorial ones—a trend that accounts for the success of both Microsoft and Disney? Part of it is simply that the world is very complicated now—much more complicated than the hunter-gatherer world that our brains evolved to cope with—and we simply can’t handle all of the details. We have to delegate. We have no choice but to trust some nameless artist at Disney or programmer at Apple or Microsoft to make a few choices for us, close off some options, and give us a conveniently packaged executive summary.

1.1M    ./scripts 58M     ./cloud9 74M     . You can also use tee to write the output to several files at the same time, as shown in this example: root@beaglebone:/opt# du ‐d1 ‐h | tee /tmp/1.txt /tmp/2.txt /tmp/3.txt Filter Commands (from sort to xargs) There are filtering commands, each of which provides a useful function: sort: This command has several options, including (‐r) sorts in reverse; (‐f) ignores case; (‐d) uses dictionary sorting, ignoring punctuation; (‐n) numeric sort; (‐b) ignores blank space; (‐i) ignores control characters; (‐u) displays duplicate lines only once; and (‐m) merges multiple inputs into a single output. wc (word count): This can be used to calculate the number of words, lines, or characters in a stream. For example: root@beaglebone:/tmp# wc < animals.txt  4  4 18 This has returned that there are 4 lines, 4 words, and 18 characters. You can select the values independently by using (‐l) for line count; (‐w) for word count; (‐m) for character count; and (‐c) for the byte count (which would also be 18 in this case). head: Displays the first lines of the input. This is useful if you have a very long file or stream of information and you want to examine only the first few lines. By default it will display the first 10 lines. You can specify the number of lines using the ‐n option. For example, to get the first five lines of output of the dmesg command (display message or driver message), which displays the message buffer of the kernel, you can use the following: root@beaglebone:/tmp# dmesg | head ‐n5   [    0.000000] Booting Linux on physical CPU 0x0   [    0.000000] Initializing cgroup subsys cpuset   [    0.000000] Initializing cgroup subsys cpu   [    0.000000] Initializing cgroup subsys cpuacct   [    0.000000] Linux version 3.13.4-bone5(root@imx6q-sabrelite-1gb-0) tail: This is just like head except that it displays the last lines of a file or stream. Using it in combination with dmesg provides useful output, as shown here: root@beaglebone:/tmp# dmesg | tail ‐n2   [   36.123251] libphy: 4a101000.mdio:00 - Link is Up - 100/Full   [   36.123421] IPv6:ADDRCONF(NETDEV_CHANGE): eth0:link becomes ready grep: A very powerful filter command that can parse lines using text and regular expressions. You can use this command to filter output with options, including (‐i) ignore case; (‐m 5) stop after five matches; (‐q) silent, will exit with return status 0 if any matches are found; (‐e) specify a pattern; (‐c) print a count of matches; (‐o) print only the matching text; and (‐l) list the filename of the file containing the match. For example, the following examines the dmesg output for the first three occurrences of the string “usb,” using ‐i to ignore case: root@beaglebone:/tmp# dmesg |grep ‐i ‐m3 usb   [    1.948582] usbcore: registered new interface driver usbfs   [    1.948637] usbcore: registered new interface driver hub   [    1.948795] usbcore: registered new device driver usb You can combine pipes together. For example, you get the exact same output by using head and displaying only the first three lines of the grep output: root@beaglebone:/tmp# dmesg |grep ‐i usb |head ‐n3   [    1.948582] usbcore: registered new interface driver usbfs   [    1.948637] usbcore: registered new interface driver hub   [    1.948795] usbcore: registered new device driver usb xargs: This is a very powerful filter command that enables you to construct an argument list that you use to call another command or tool. In the following example, a text file args.txt that contains three strings is used to create three new files. The output of cat is piped to xargs, where it passes the three strings as arguments to the touch command, creating three new files a.txt, b.txt,

[    1.948637] usbcore: registered new interface driver hub   [    1.948795] usbcore: registered new device driver usb You can combine pipes together. For example, you get the exact same output by using head and displaying only the first three lines of the grep output: root@beaglebone:/tmp# dmesg |grep ‐i usb |head ‐n3   [    1.948582] usbcore: registered new interface driver usbfs   [    1.948637] usbcore: registered new interface driver hub   [    1.948795] usbcore: registered new device driver usb xargs: This is a very powerful filter command that enables you to construct an argument list that you use to call another command or tool. In the following example, a text file args.txt that contains three strings is used to create three new files. The output of cat is piped to xargs, where it passes the three strings as arguments to the touch command, creating three new files a.txt,

which a drawing imported into a text document can no longer be altered, but must be changed in the original graphics program and reintroduced into the text document.) Out of the box the Star was multilingual, offering typefaces and keyboard configurations that could be implemented in the blink of an eye for writing in Russian, French, Spanish, and Swedish through the use of “virtual keyboards”—graphic representations of keyboards that appeared on screen to show the user where to find the unique characters in whatever language he or she was using. In 1982 an internal library of 6,000 Japanese kanji characters was added; eventually Star users were able to draft documents in almost every modern language, from Arabic and Bengali to Amharic and Cambodian. As the term implied, the user’s view of the screen resembled the surface of a desk. Thumbnail-sized icons representing documents were lined up on one side of the screen and those representing peripheral devices—printers, file servers, e-mail boxes—on the other. The display image could be infinitely personalized to be tidy or cluttered, obsessively organized or hopelessly confused, alphabetized or random, as dictated by the user’s personality and taste. The icons themselves had been painstakingly drafted and redrafted so they would be instantaneously recognized by the user as document pages (with a distinctive dog-eared upper right corner), file folders, in and out baskets, a clock, and a wastebasket. Thanks to the system’s object-oriented software, the Star’s user could launch any application simply by clicking on the pertinent icon; the machine automatically “knew” that a text document required it to launch a text editor or a drawing to launch a graphics program. No system has ever equaled the consistency of the Star’s set of generic commands, in which “move,” “copy,” and “delete” performed similar operations across the entire spectrum of software applications. The Star was the epitome of PARC’s user-friendly machine. No secretary had to learn about programming or code to use the machine, any more than she had to understand the servomechanism driving the dancing golf ball to type on an IBM Selectric typewriter. Changing a font, or a margin, or the space between typed lines in most cases required a keystroke or two or a couple of intuitive mouse clicks. The user understood what was happening entirely from watching the icons or documents move or change on the screen. This was no accident: “When everything in a computer system is visible on the screen,” wrote David Smith, a designer of the Star interface, “the display becomes reality. Objects and actions can be understood purely in terms of their effects on the display.