** UnhandledExceptionEventHandler :: OFFICIAL LC / CHATTER THREAD ** - Page 1455 - Computer Technical Help

fread will read from a file into a buffer like this:

fread(buffer, n, nmemb, file pointer)

n is the number of bytes you are requesting nmemb times, so if you do fread(buffer, 1, 8192, fp) you are requesting 1 byte read 8192 times, vs 8192 bytes 1 time. Then it will return whatever the successful number of nmemb reads was.

but fread will (presumably) read byte by byte anyway into its own internal buffer using getc, so the assumption can be made it doesn’t matter which one you use. But implementations of fread can vary because the standard doesn’t really necessitate n * nmemb calls to getc. It may implement it completely differently if it wishes, as long as it follows the standard.

The number of getc calls is important because it makes a system call which is very expensive.

Quote

11-15-2018 , 05:43 PM

#36353

jjshabado

Carpal Tunnel

Join Date: Jul 2006 Posts: 22,732

I get a lot of the recent complaints about SO, but this is like a perfect example of where it’s good. The weird super edge case debate gets moved to the side / hidden and what you need to know is obvious.

It’s far from perfect (especially culturally), but damn am I glad it exists.

Quote

11-15-2018 , 05:51 PM

#36354

microbet

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Thanks jmakin

Quote

11-15-2018 , 09:11 PM

#36355

jmakin

banned

Join Date: Jan 2008 Posts: 30,120

I wrote a decently sized application in C today and my brain is absolutely fried, i came across that comment and i guess it triggered me more than it should have

Quote

11-15-2018 , 11:47 PM

#36356

RustyBrooks

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Quote:

Originally Posted by jmakin

Ok maybe i am just being nitpicky. I always tend to call with (n,1).

When you do it this way you can't tell how many bytes were read when it fails, which is sometimes useful to know

Quote

11-15-2018 , 11:54 PM

#36357

RustyBrooks

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Join Date: Feb 2006 Posts: 24,647

Also, this is going out on a limb a bit, but I think POSIX specifies that fread should be an equivalent set of fgetcs. If you have a POSIX compiler, then it should always do that.

Not all compilers are POSIX compliant, and I wouldn't be surprised to find that some supposedly POSIX compliant compilers could have bugs or deviations from spec.

A few days ago I realized that stdc++ and libc++ have different behavior for a function, streambuff::in_avail, that tells you whether or not a stream has bytes that can be read. I can't remember which is which now, but in one of them, the function always says "no" even if the answer is "yes"

A program that we download/compile started breaking for us because they switched from one to the other.

Quote

11-15-2018 , 11:56 PM

#36358

jmakin

banned

Join Date: Jan 2008 Posts: 30,120

Quote:

Originally Posted by RustyBrooks

When you do it this way you can't tell how many bytes were read when it fails, which is sometimes useful to know

Yea i know, but the reads i’m doing i want all or nothing

Quote

11-16-2018 , 02:37 AM

#36359

microbet

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Join Date: Jan 2005 Posts: 56,580

You can do this

Code:

function getValues(param) {
  let x = param + 2;
  let y = param + 3;
  let z = param + 4;
  return [x, y, z];
}

a = getValues(2);
alert(a[0]);  //4
alert(a[1]);  //5
alert(a[2]);  //6

Is there a way to do like this and just assign the return to variables in javascript? Seems like there might be some way to fat arrow something.

Code:

function getValues(param) {
  let x = param + 2;
  let y = param + 3;
  let z = param + 4;
  return x, y, z;
}

(a, b, c) = getValues(2);

(that doesn't work)

you can do this in python

Code:

def getValues(param):
   x = param + 2
   y = param + 3
   z = param + 4

(a, b, c) = getValues(2)
print(a)  #4
print(b)  #5
print(c)  #6

Quote

11-16-2018 , 03:50 AM

#36360

fredd-bird

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What you're looking for there is destructuring which is something that got added fairly recently in JS.

If we return that array of values, then we can destructure that into another array with those variables. Like this:

Code:

function getValues(param) {
    let x = param + 2;
    let y = param + 3;
    let z = param + 4;
    return [x, y, z];
}

let [ a, b, c ] = getValues(2);
console.log(a) 
console.log(b) 
console.log(c)

If you return an object like this, you can destructure it with this syntax. Note that your variable names on the left must match the variable names in the return value, since the return object actually looks like this: { x: 6, y: 7, z: 8 }

Code:

function retValues(param) {
    let x = param + 2;
    let y = param + 3;
    let z = param + 4;
    return { x, y, z };
}


let { x, y, z } = retValues(4) 
console.log(x)
console.log(y)
console.log(z)

Quote

11-16-2018 , 04:10 AM

#36361

ChrisV

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Join Date: Jul 2004 Posts: 40,336

You could just return them as properties on an object also. That way they have names.

Quote

11-16-2018 , 11:03 AM

#36362

microbet

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Join Date: Jan 2005 Posts: 56,580

Thanks both.

I had heard someone talk about destructuring as a new feature in a JS podcast, but it was just talk, they don't really spell out code in podcasts. Now I know what they were talking about.

Chris, yeah. Either an object or array works, I was mostly curious, but the result goes in a very small function never to be used again and it seems more elegant to me to skip having to name the array or object.

Quote

11-18-2018 , 01:49 PM

#36363

microbet

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Join Date: Jan 2005 Posts: 56,580

Quote:

Originally Posted by fredd-bird

Skip Notepad++ and go straight to VS Code or get good at Vim.

I'm still splitting time on Notepad++ and Vim, but getting my .vimrc file set up better is making Vim nicer. I still need to get auto-completion.

(tabstop and shiftwidth=3, colorscheme evening, Lucinda_console font at 12 for my old eyes.)

Quote

11-18-2018 , 02:40 PM

#36364

Victor

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Join Date: Jul 2003 Posts: 72,156

Pretty sure you can use the array reduce function

Quote

11-20-2018 , 11:29 AM

#36365

stlows

journeyman

Join Date: Apr 2016 Posts: 224

I have an interview for a job.

I have two years experience in .Net and the job is .Net, MVC, Web, Javascript, Scrum etc... standard stuff that I do regurlary.

They told me there is a 75 minutes test. What would be the best way to prepare for that kind of test? What are the generally asked question in those type of test?

Thanks

Quote

11-20-2018 , 11:31 AM

#36366

kerowo

lolcat

Join Date: Nov 2005 Posts: 37,190

Check Glassdoor.com and see if they have anything on the tests during interviews.

Quote

11-20-2018 , 01:29 PM

#36367

microbet

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Join Date: Jan 2005 Posts: 56,580

Quote:

Originally Posted by microbet

omni-completion is pretty cool. I can see being able to really fly when you are good at it.

Quote

11-20-2018 , 04:18 PM

#36368

Grue

Pooh-Bah

Join Date: Mar 2004 Posts: 5,667

Spent last 2 days trying to fix memory leak in express with no luck

Quote

11-20-2018 , 04:18 PM

#36369

PJo336

THRILLHOUSE!

Join Date: Mar 2007 Posts: 22,158

Quote:

Originally Posted by microbet

omni-completion is pretty cool. I can see being able to really fly when you are good at it.

I really liked whatever completion plug in I used but getting language based auto complete was tough. Like showing functions on an object. Seemed silly to not just use vs code at that point, but then I'm not as leet

Quote

11-20-2018 , 04:19 PM

#36370

PJo336

THRILLHOUSE!

Join Date: Mar 2007 Posts: 22,158

Quote:

Originally Posted by Grue

Spent last 2 days trying to fix memory leak in express with no luck

Haha I think the common node solution is just restart the process once a day.

How'd you go about debugging this? I write so much node but do so little debugging

Quote

11-20-2018 , 04:21 PM

#36371

jmakin

banned

Join Date: Jan 2008 Posts: 30,120

Do set noexpandtab on vim too, unless you’re into that sort of thing

Quote

11-20-2018 , 04:22 PM

#36372

PJo336

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Join Date: Mar 2007 Posts: 22,158

Suzzer, you still working in serverless land? How's that going?

Quote

11-20-2018 , 05:02 PM

#36373

suzzer99

Save the Cheerleader, Save the World

Join Date: Nov 2005 Posts: 99,984

Quote:

Originally Posted by Grue

Spent last 2 days trying to fix memory leak in express with no luck

I would love love love a writeup of this. You should do a medium post or something. Or at least just give us a synopsis of the problem and what you've tried so far here.

Quote

11-20-2018 , 05:07 PM

#36374

suzzer99

Save the Cheerleader, Save the World

Join Date: Nov 2005 Posts: 99,984

Quote:

Originally Posted by PJo336

Suzzer, you still working in serverless land? How's that going?

Great. Tomorrow I'm giving my first real presentation to our group of what I've been working on so far.

Here's the "What have I been doing for the last 3 months?" slide:

Quote:

Various code pipelines driven by commit to source control
Git branching strategy and workflow
C# lamdbas/testing/Visual studio solution workflow
Node lambdas with testing
API Gateway generated from swagger
CI/CD flow and testing platform for front end
Workflow for react site with cognito
POC cognito login and registration flows back-end with lambdas
Internal only access for dev/test sites, living documentation, future monitoring dashboards, etc.
Draft architecture for donor portal and other cognito-based internal apps