It has two very different meanings, that you would have to distinguish by context. One meaning is just expressing that we have limitations. If you don't know something, that's just tough, you don't know it and you have to live with that. You don't have information if you don't have that information. The other meaning is that not only are there gaps in our knowledge, but often we don't even know what the gaps in our knowledge are. I don't know how to speak Finnish. That's a gap in my knowledge that I know about. I know that I don't know how to speak Finnish. But there are gaps in my knowledge that I'm not even aware of. That's where you can say "You don't know what you don't know" meaning that you don't even know what knowledge you are missing.

but in essence I expect OP means Rumsfeld's "unknown unknowns"

I wouldn't necessarily go as far as call this a "phrase" per se.

Socrates' dictum may be wise, but I think there's a world of difference between OP's acknowledgement that the amount of things one doesn't know is indeterminate, and Socrates' assertion that, for him, everything falls into that category.

But there are also unknown unknowns – the ones we don't know we don't know.

We also know there are known unknowns; that is to say we know there are some things we do not know.

Some risk management techniques urge practitioners to consider the "known unknowns" and the "unknown unknowns"

Incidentally, I'd add that it can also be used in looking toward the future, in awareness that we lack such a crystal ball: We base our plans on our knowledge, and there'll be times where we know there is a gap in that knowledge, but we're also aware that there may be things we can't possibly foresee, because "we don't know what we don't know".

Yogi also said that "Half the lies they tell about me aren't true"

"I didn't say a lot of the things that I said"

"It ain't over 'til it's over,"

"You can observe a lot by watching."

Generally speaking, it would not be a good way to express something in formal writing, unless perhaps you were deliberately injecting humor.

This is the essence of "You don't know what you don't know," only it's being expressed in a comical way, much like Yogi Berra might have said. (To those unfamiliar with the Yogi Berra reference, he was a professional baseball player who was reknowned for his wry way of saying things, such as, "It ain't over 'til it's over," and, "You can observe a lot by watching."

Yet, in all these instances, life offers no crystal ball; there's no way of knowing what the future holds, or to be cognizant of something we are unaware of. This is the essence of "You don't know what you don't know," only it's being expressed in a comical way

Had I known the van was going to overheat, I would have driven the car instead.

If I had known you were going to get such bad grades on your report card, I wouldn't have let you go to the dance last weekend.

If I had known your plane was going to be two hours late, I wouldn't have rushed to the airport.

That said, you couldn't know what you didn't know, but now you know.

Comedian Henny Youngman was famous for one-liners delivered in a deadpan manner. Much of his humor was both wry and dry.

I intend to live forever. So far, so good. Whenever I think of the past, it brings back so many memories. I think it's wrong that only one company makes the game Monopoly. If it's a penny for your thoughts and you put in your two cents worth, then someone, somewhere is making a penny. What's another word for Thesaurus? I used to work in a fire hydrant factory. You couldn't park anywhere near the place.

Adding another Steven Wright gem: "24 hour banking? I don't have time for that."

Comedian Henny Youngman was famous for one-liners delivered in a deadpan manner. Much of his humor was both wry and dry. For example, his most famous line: Take my wife ... please. If you never saw the delivery, "Take my wife" was said as if he was using his wife as an example to set up a situation, as in "Take my wife [for example]." After a brief pause, the "please" turned it into a request.

Some humor is just funny on a surface level, or incorporates words that sound funny. What makes dry humor unique is that it isn't always obviously funny, especially with a deadpan delivery; you often need to think about it. The humor is entirely within the meaning of the words.

I'm sorry I hurt your feelings when I called you stupid. I really thought you already knew.

Inside every older person is a younger person wondering what the hell happened.

I swear; if my memory was any worse, I could plan my own surprise party.

"Wry" evolved from a meaning of "to twist". Applied to humor, it refers to humor that is bitterly or disdainfully ironic or amusing; distorted or perverted in meaning; warped, misdirected, or perverse; words that are unsuitable or wrong; scornful and mocking in a humorous way--it covers a lot of territory (see WordReference.com).

What is the difference between “wry” and “dry” humor?

"Dry" humor is often called deadpan humor because it is delivered with a straight face and a serious tone, as if it is not intended to be funny.

Wry humor can be delivered in a deadpan manner.

cleverly and often ironically or grimly humorous

British HumorDry humor is particularly associated with British humor. Fawlty Towers, a British television comedy that aired from 1975 to 1979 is considered an unusually good example of dry humor. The series is set in a family run seaside hotel operated by a cynical and snobbish man, played by John Cleese, who finds himself in constant conflict with hotel guests. No matter how outlandishly silly each episode becomes, there is never any sense that the characters are trying to be funny.

Dry humor is a delivery technique. As such, it shouldn't be confused with specific types of humor or with sarcasm. Sarcasm is delivered without humor because it's generally not funny but intended to mock or convey contempt. Dry humor pertains to something funny.

Humor is based on a sense of the unexpected, inexplicable, ridiculous and ironic. Dry humor can enhance these qualities to make things more humorous. For example, humor that is delivered as if it were not a joke may feel more surprising and odd.

Dry humor is a comedic technique of delivering humor as if you didn't intend to be funny.

The basic rule of thumb is: "I'm not aware of all types of security exploits. I must protect against those I do know of and then I must be proactive!".

A good heuristic is to not trust the libraries you did not write either.

Within functions, you may want to check that you are not referencing something that is not valid (i.e., null) and that array lengths are valid before referencing elements, especially on all temporary/local instantiations.

In this practice, only errors from outside the program's control are to be handled (such as user input); the software itself, as well as data from within the program's line of defense, are to be trusted in this methodology.

This repository contains the source code for:

ConPTY, or the Windows PTY

Addendum: seven years later, Windows finally supports pseudoconsoles. If you are running on Windows 10 v1809 or later, this new API should solve your problem.

When you have a pipeline, unbuffer must be applied to each element except the last (since that doesn't have its output redirected). Example: unbuffer p1 | unbuffer p2 | unbuffer p3 | p4

unbuffer disables the output buffering that occurs when program output is redirected. For example, suppose you are watching the output from a fifo by running it through od and then more.    od -c /tmp/fifo | more You will not see anything until a full page of output has been produced. You can disable this automatic buffering as follows:    unbuffer od -c /tmp/fifo | more

Going through different search systems brings us some fruits in the form of indistinct mumbling about the untimely closed I/O data streams, TTYs and PTYs (pseudoterminals) and all the rest of it.

because while dealing with interactive programs one often come across numerous hidden traps which doesn’t usually happen with ordinary sh-scripts. Though fortunately or may be not, but most of these problems generally turn up within first five minutes of the work under the script. The symptoms typically look like that author can’t pass the authentication from the script.

Of course you must not use plain-text passwords and place them directly into scripts. You even must not use telnet protocol at all. And avoid ftp, too. I needn’t say why you should use ssh, instead, need I? And you also must not plug your fingers into 220 voltage AC-output. Telnet was chosen for examples as less harmless alternative, because it’s getting rare in real life, but it can show all basic functions of expect-like tools, even abilities to send passwords. BUT, you can use “Expect and Co” to do other things, I just show the direction.

But the imho easiest solution he oversaw…

Apart from some dodgy English (‘let’s don’t’ for example)

Yes, autoexpect is a good tool, but it is used just to automatically create TCL-expect scripts, by watching for user. So it’s can be equal to writing expect-scripts by hand.

It's essential to note that all the experiments are valid for FreeBSD and I can't guarantee they'll give the same results on other operating systems.

now I'll tell you what really takes place when we start interactive applications from shell scripts

Certainly, if for some reason Python doesn't suit you either you can install, let us say, PHP language. Well, I think you realize that the searching of suitable solution can go on for a long time and may be only MS Visual Basic will be lacking in the list of results. So, I believe the time has already approached to put it all aside and come to to the Point.

However, if in spite of all the attractiveness of the foregoing method and all the arguments of the expect authors (see FAQ) you have made up your mind not to use expect, then you are either too lazy or entirely poisoned by Perl. Well, in this case your salvation lies in the installation of the corresponding Perl-module (http://sourceforge.net/projects/expectperl), which is supposed to support all the functions of the original expect

you can take the opportunity of using Python as a corresponding module pexpect is written for it (http://pexpect.sourceforge.net). It's clear that Python language should be installed on the system beforehand

By the way, the README file of the expect says there is a libexpect library that can be used to write programs on C/C++ which allows to avoid the use of TCL itself. But I'm afraid, this subject is beyond this article. Besides authors of expect themselves seem to prefer expect-scripts to the library.

But in all this incongruous abundance you'll certanly find the links to expect It's just what is wanted: the tool, which is traditionally used to communicate automatically with interactive programs. And as it always occurs, there is unfortunately a little fault in it: expect needs the programming language TCL to be present. Nevertheless if it doesn't discourage you to install and learn one more, though very powerful language, then you can stop your search, because expect and TCL with or without TK have everything and even more for you to write scripts.

Really you are not the first to run into such a problem

At first you feel confused because usual pipe constructions such as: $ echo luser && echo TopSecret | telnet foo.bar.com fail you and the problem which seemed so plain on the face of it grows into “mission impossible”.

among these scripts there certainly will be those to cooperate with interactive applications such as telnet, ftp, su, password, ssh

As a result of all this in a couple of weeks I had a working version of empty (http://www.sourceforge.net/projects/empty) which allows to start interactive programs and communicate with them using FIFO-files

one of the oldest problems was the use of Command-line interactive programs in UNIX shell-scripts

In some cases empty can be the simplest replacement for TCL/expect or other similar programming tools because empty:

empty is an utility that provides an interface to execute and/or interact with processes under pseudo-terminal sessions (PTYs). This tool is definitely useful in programming of shell scripts designed to communicate with interactive programs like telnet, ssh, ftp, etc.

can be easily invoked directly from shell prompt or script

#!/bin/sh
empty -f -i in -o out telnet foo.bar.com
empty -w -i out -o in "ogin:" "luser\n"

#!/usr/bin/expect

spawn telnet foo.bar.com 
expect ogin {send luser\r}

does not use TCL, Perl, PHP, Python or anything else as an underlying language is written entirely in C has small and simple source code can easily be ported to almost all UNIX-like systems

does not use TCL, Perl, PHP, Python or anything else as an underlying language

Operating systems implement a command-line interface in a shell for interactive access to operating system functions or services.

Today, many users rely upon graphical user interfaces and menu-driven interactions. However, some programming and maintenance tasks may not have a graphical user interface and may still use a command line.

If no file is detected (in case, it's being run as part of a script or the command is being piped)

The command also can be run in silent mode (tty -s) where no output is produced, and the command exits with an appropriate exit status.

The role of the terminal emulator process is:

Screen and Tmux are used to add a session context to a pseudoterminal, making for a much more robust and versatile solution. For example, each provides terminal persistence, allowing a user to disconnect from one computer and then connect later from another computer.

The terminal emulator process must also handle terminal control commands, e.g., for resizing the screen.

The Windows Console was extended to have a PTY interface called ConPTY in 2018.

In the BSD PTY system, the slave device file, which generally has a name of the form /dev/tty[p-za-e][0-9a-f], supports all system calls applicable to text terminal devices.

Example

Streams could also be used for inter-process communication, by connecting two processes to pseudoterminals.

STREAMS originated in Version 8 Research Unix, as Streams (not capitalized).

In this framework, a stream is a chain of coroutines that pass messages between a program and a device driver (or between a pair of programs)

The question talks about stdout but the title mentions stdin. I think the title is wrong.

If there are some pipe between these commands, you need to flush stdout. for example: script -q /dev/null commands... | ruby -ne 'print "....\n";STDOUT.flush'

unbuffer works with piping to less. That may be an easier syntax than what you've got.

Is there an OS agnostic way of doing this? I like the script command on macOS because you don't have to wrap the command in quotes. The script runs and sends output to the tty which is duplicated in the supplied file, but I can't seem to get the linux version to behave the same way... I'm probably doing something wrong. So what's the equivalent linux script command for this on macOS: script -q -t 0 tmp.out perl -e 'print "Test\n"' Test cat tmp.out Test

The quirky looking printf is necessary to correctly expand the script's arguments in $@ while protecting possibly quoted parts of the command (see example below).

I came up with the following little helper function

faketty() { script -qfc "$(printf "%q " "$@")" /dev/null }

faketty() {
    script --return -qfc "$(printf "%q " "$@")" /dev/null
}

⟫ faketty python -c "import sys; print sys.stdout.isatty(); exit(1)" ; echo $?
True
1

You probably want to use the --return option, if your version of script has it, to preserve the child process' exit code.

This doesn't work in cases where the component checking for interactivity is looking at the $- shell variable for an "i"

If you want to pipe it into something interactive, like less -R, where terminal input goes to less -R, then you need some extra trickery. For example, I wanted a colourful version of git status | less. You need to pass -R to less in order that it respect the colours, and you need to use script to get git status to output colour. But we don't want script to keep ownership of the keyboard, we want this to go to less. So I use this now and it works well: 0<&- script -qfc "git status" /dev/null | less -R . Those first few characters close stdin for this one commmand.

.[color]
  ui = always
  status = always

0<&- script -qfc "git status" /dev/null | less -R

if you really need the child process to see a TTY, you can create a PTY.

0</dev/null script --quiet --flush --return --command "$(printf "%q " "$@")" /dev/null

I also added --return and used long options, to make this command a little less inscrutable:

Too new to comment on the specific answer

I'm trying to do the opposite of "Detect if stdin is a terminal or pipe?".

In many computing contexts, "TTY" has become the name for any text terminal, such as an external console device, a user dialing into the system on a modem on a serial port device, a printing or graphical computer terminal on a computer's serial port or the RS-232 port on a USB-to-RS-232 converter attached to a computer's USB port, or even a terminal emulator application in the window system using a pseudoterminal device.

This is hard because Apple does not want you to and a failed installation might render the ipad useless.

Also you will not be able to run any iOS apps anymore obviously.

If you want to run a full fletched linux OS on the ipad an option is to jailbreak the ipad and try to install linux. This is hard because Apple does not want you to and a failed installation might render the ipad useless. Also you will not be able to run any iOS apps anymore obviously.

A well formulated question deserves a proper answer

Opening "xterm" in "iSH" is like starting a new virtual terminal from a virtual terminal you are already in ("iSH").

As far as the 'iSH' app is concerned: it seems that it merely emulates a virtual terminal.

A "tty" neither has anything to do with rendering text.

The virtual terminal process resides in kernel space (called the console).It reads from the "tty", say the output from the "ls" process and renders the text. It interacts with the VGA driver to do so.

Then who is responsible for the actual rendering?

The (virtual) terminal (not the "tty") plays a central role here

I didn't get exactly how pty came into picture and what is the usage of that. Looking forward to get more info on that.

How is related /dev/ack with /dev/tty?

as you may have guessed, things get even more complicated when you start running pseudo terminals inside pseudo terminals, à la screen(1) or ssh(1).

To facilitate moving the terminal emulation into userland, while still keeping the TTY subsystem (session management and line discipline) intact, the pseudo terminal or pty was invented.

By default, fork(2) places a newly created child process in the same process group as its parent, so that e.g. a ^C from the keyboard will affect both parent and child.

But the shell, as part of its session leader duties, creates a new process group every time it launches a pipeline.

Job control is what happens when you press ^Z to suspend a program, or when you start a program in the background using &

A job is the same as a process group.

Work with the open source languages you love without the hassles of runtime management.

Your Open Source Supply Chain Is Bigger Than You Think.Reduce your security, risk, and compliance load. Let us scan your Python, Perl, and Tcl application for you and help you gain the transparency you need to reduce open source risk.

but our first title The Detail will be pulled from Steam and AppStore at some point.

Work-life balance However, I recently understood that while we were working on the game, I broke the one and only rule I set for the founders of the company: always family first. My wife was expecting our second child and I was working long days at the office, and I became obsessed with making sure the game is as good as possible. The same probably applies to everyone in the team, since we shared love and passion for the franchise.

On iOS, the figures are close to the same except there the game has been for free for a while already.

no big deal, the episodes are all for Steams bottom price

I just don't understand why a finished episodically released game is still offered episodic.

A charming little romp through a realm of lateral thinking.

Good fun if you think along this sort of wavelength!

Admittedly, some of the puzzles can be a little bit obtuse, particularly without any sort of hint-system to ensure you're thinking along the right lines, but still perfectly 100%able even without that.

Anytime before your items ship, you may cancel your order for a full refund, no questions asked. And when you do get your items, if you don't think what you ordered lives up to expectations, we'll also refund you 100% and even pay for return shipping.

For those who are wondering about the name, Bear Raid is a real phrase used to describe when a stock price is intentionally lowered through short selling and rumors.

Factory FunNER is the sequel and a very solid improvement to Factory Fun. It uses hexes instead of squares to allow more creative building, and some subtle improvements to scoring, length, and machine placement rules really improve things.

#2 Non-real-time variant - What about groups who don't like that real-time part of the game? We really think that is the best way to play, but we realize it isn't a fun or even possible option for everyone. We're including an alternative rule that removes all the speed elements and is still fun (in a different way).

Building a wonky factory is way more fun than it has any right to be - and being rewarded for leaving last turn's pieces where they are (or punished for moving them) means that you're always working on top of the mess you made last turn, though you're never completely stuck.

Around &Bigger the box is bigger: 75mm high instead of 45mm or so.That was the main reason for the name &Bigger. The first edition does fit in its box but very tight. Because the first factory used bigger cardboard than planned. They told me about this "upgrade" after they produced the game. The thicker tiles (about 2.5mm) did feel good for the game so the &Bigger edition has the same

I don't know if I am allowed to link here

Only the Starter Kit is available in this reboot. The Starter Kit is FREE, in order to distribute it as widely as possible. This goal of this Kickstarter campaign is to introduce Clash of Deck to the whole word and to bring a community together around the game. If the Kickstarter campaign succeeds, we will then have the necessary dynamic to publish additional paid content on a regular basis, to enrich the game with: stand-alone expansions, additional modules, alternative game modes..

Stretch goals are mainly game quality improvement we will be able to finance thanks to your help. No extension or extra-scenario still to be designed and playtested that could delay the delivery of the games. Just of few goals to make them event better component wise.

I bought this game and hope it will look like Carcassonne.But, my first impression of this lead me to compare this with Go.At the present, I am teaching to anyone that this game is Go with modular board.Yep, Bought this new and Go was my first thought on this, also. Definitely much closer to Go than Carcassonne.

The developers allowed for players to play their own level of challenge whether it's using the active pause, fast forward or multi-level undo function.

This game is severely underrated. I genuinely do not understand all of the negative backlash it gets. It's a solid scribblenauts game with a ton of replay value and a way to past the time with friends. It's not perfect, as the motion controls do drag it down slightly, and some of the minigames offered are less than great, however it does not deserve the overwhelming hate it gets. It's a solid title in the series.

I truly TRULY do not get the hate of this game. I am in my 40's. Played with 2 boys, 10 and 12. And we all had an amazing time playing the board game version of this for an hour. When it was over, the boys said, LETS PLAY IT AGAIN! The game is deep. Also has original sandbox mode with new levels. When they were about to leave, I surprise them by giving them the game as a gift. They were SO excited (and, I will simply buy another one for myself) I am simply BAFFLED at the hate and negativity for this game. Sure, a couple of the mini-games are not top notch. But there are many great ones within. At $40, solid deal. At $20 sale in most places, you have got to be kidding me. Steal it at that price. If you like Scribblenauts or are new to the Scribblenauts world, just buy it.

The game is lame and the main gimmick of writing stuff is being shat on with the horrendous gameplay. If you have a very unique formula, don't try to change it.

Yes, it shares the name and the look of those previous games, but it lacks the all-important creative heart of its predecessors, and ends up being a by-the-numbers affair that goes through the motions in a shallow attempt to turn Scribblenauts' unique premise into a multiplayer party game.

but it’s an extra feature that adds to a game that would still feel complete without it.

the lack of touchscreen support is an odd omission considering both games previously appeared on 3DS and Wii U,

Windows Subsystem for Linux provides a Linux-compatible kernel interface developed by Microsoft and containing no Linux code

Functional UNIX[edit] Broadly, any Unix-like system that behaves in a manner roughly consistent with the UNIX specification, including having a "program which manages your login and command line sessions";[14] more specifically, this can refer to systems such as Linux or Minix that behave similarly to a UNIX system but have no genetic or trademark connection to the AT&T code base.

Some add a wildcard character to the name to make an abbreviation like "Un*x"[2] or "*nix", since Unix-like systems often have Unix-like names such as AIX, A/UX, HP-UX, IRIX, Linux, Minix, Ultrix, Xenix, and XNU. These patterns do not literally match many system names, but are still generally recognized to refer to any UNIX system, descendant, or work-alike, even those with completely dissimilar names such as Darwin/macOS, illumos/Solaris or FreeBSD.

Genericization or "loss of secondary meaning"

A generic trademark, also known as a genericized trademark or proprietary eponym, is a trademark or brand name that, because of its popularity or significance, has become the generic term for, or synonymous with, a general class of products or services, usually against the intentions of the trademark's owner.

Windows Subsystem for Linux, also known as WSL, is a compatibility layer for running Linux binary executables natively on Windows 10 using a Linux image

Not to be confused with Unix, Unix-like, or Linux.

The TCP/IP model is a more concise framework, with only 4 layers:

For Mac OS X, the syntax seems to be:

This question does not show any research effort; it is unclear or not useful Bookmark this question. Show activity on this post. I'm trying to filter the output of the mpv media player, removing a particular line, but when I do so I am unable to control mpv with the keyboard. Here is the command: mpv FILE | grep -v 'Error while decoding frame' When I run the command, everything displays correctly, but I am unable to use the LEFT and RIGHT keys to scan through the file, or do anything else with the keyboard. How do I filter the output of the program while retaining control of it?

Quite a lot of programs actually detect if their output goes to a file (e.g. try man | grep -F a and you will not be able to scroll back and forth).

perl -ne 'chomp(); if (-e $_) {print "$_\n"}'

xargs -i sh -c 'test -f {} && echo {}'

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Gilles has written an excelent answer here (see unix.stackexchange.com/a/105655/49721) explaining why "A space-separated list of file names doesn't really work: what if one of the file names contained spaces?"

What produces that text, and what do you want to use it for?

If it's a list of actual pathnames, just replacing spaces by newlines may obviously mangle pathnames that contain embedded spaces, such as /User/myself/VirtualBox VMs/.

2 out of 3 people in my household do not find it easy to understand. Maybe that is is not representative, but keep in mind that something you yourself understand (or in this case think you understand) always seems easy.

I think you can do more with sed as it is an editor rather than simply translate characters.

Notice the use of Enter key after backslash in the sed command.

sed can do so much more, but is totally overkill for this. tr is the right tool for THIS job, but knowledge of sed and regexes will certainly come in handy later!

For path names with newlines it is better to quote each pathname.

But we can use a two characters delimiter: / (space slash) That pair of characters could only exist at the beginning of a new (absolute) path:

The question on the title: replace space with new line The simple, quick, brute force solution is to do exactly that, replace all spaces with new lines:

But in your question you are listing a list of paths:

Using the solution above will not work for filenames with spaces (or newlines).

Although echo "$@" prints the arguments with spaces in between, that's due to echo: it prints its arguments with spaces as separators.

If a program receives file names as arguments, don't join them with spaces. Use "$@" to access them one by one.