Im really new to node and feel like I understand nothing. I was watching a tutorial where the fs.writeFileSync creates a new file. However my code doesn't work and no file is being created-does someone know why? Also why do I need
var fs=require("fs");
? As I understand fs is a build in module and if we require something, there should be another file that exports something (which we require using the fs module)? Node is kind of hard to understand and would appreciate some explanation! Thanks
var fs=require("fs");
fs.writeFileSync("contents.txt","Thats a new file")
console.log(fs.writeFileSync("contents.txt").toString());
fs is indeed a node built-in module, and as other modules, you must require it to use its capabilities. the file you're referring is present internally, so you don't have to npm install it.
And regarding your code, fs.writeFileSync should work as you used it, however, when you tried to print it, you used this function again, this time with no contents, what probably caused the mix-up.
Code that should work perfectly is:
//Requiring the fs module in order to use it later on
var fs = require('fs');
//Writing "Thats a new file" as text to a new file called "contents.txt" in the same directory as the script file.
fs.writeFileSync('contents.txt', 'Thats a new file');
//If you want to print the file, read it, like so.
console.log(fs.readFileSync('contents.txt'));
Also, I think you should continue reading about node's async capabilities so you can understand better this technology and what is it good for. This is one site you can learn from but there are a lot of other good ones out there.
Related
I used this library, mem-fs-editor (https://github.com/sboudrias/mem-fs-editor), in a Yeoman generator a few weeks ago. It worked nicely, but now I tried to use it again in a different scope and I couldn't do anything. Obs: I used it because this is the library Yeoman provides to handle the file system.
In Yeoman Generators we can copy files from a template folder, passing values to inject in the code, to a different folder. And that's precisely what I need, but I can't use Yeoman this time.
I tried the same code I used in my Yo Generator, but it don't work. So I'm not sure how mem-fs works. No errors are thrown and even the code provided by the author of the project don't work to me.
I tried this (and some other things with copyTpl) with no success
var memFs = require('mem-fs');
var editor = require('mem-fs-editor');
var store = memFs.create();
var fs = editor.create(store);
console.log(fs.write('./somefile.js', 'var a = 1;'));
Anyone knows how it works or what else I can do to make this happen?
mem-fs-editor author here.
mem-fs stands for memory file-system. All the files you creates are stored in memory and won't get written to disk until you call:
editor.commit(callback);
Yeoman does that automatically for you. It is this way with Yeoman to collide every file changes together and then being able to only prompt for file conflicts once (rather than everytime a single file is being written to).
for some reason I can't get my require to work, it should just find both models fine but the path for the file just won't work.
app
models
user.js
match.js
server.js
Seems like a simple fix but cannot seem to do it myself right now. I'm using (var User = require('/app/models/user.js');)
Thanks guys.
Actually you also can write it as,
var User = require('./app/models/user')
without even putting .js at the end, as it is added by default.. Just a tip to know :)
and here ./ means the current directory.
Hope it helps :)
I am new here and pretty new to Node.js. I got Express working fine, connecting to MySQL (database) is going fine, and socket io is working fine.
But I decided to split many of these features up in separated files. To keep my main JS file nice and clean. I made it possible to get variables from other js files back to my main.js script. Either using exports, or global. I find global working easier since most of them are functions. It's all working fine to this point.
But now the issue that I am having. I'm loading 3 js files in my main.js file. I am requiring the first js file, I call the function that is in that js file and store the result in a variable. That's going fine. But now the second js file is suppose to use or grab this variable, and that isn't working.
My question is, how do I make that work?
It is a matter of your design.
You should use module.exports to return a variable from a file.
Example:
file1.js
function someFunction() {return true;}
module.exports = someFunction();
main.js
console.log(require('./file.js')); // true
So, if the second file depends on the variable from the first file, you may also require the file1.js in the second one.
Or, export a function that accept one parameter in the second file. The main file should then use the variable from first file to call the function.
I am able to copy a file in node.js using the following:
var readStream = fs.createReadStream(fromFilePath);
readStream.pipe(fs.createWriteStream(toFilePath));
The question is how to also copy/keep the modified time (mtime) like in a regular file copy command.
There are methods in the fs module to access mtime:
var stat = fs.statSync(fromFilePath);
fs.utimesSync(toFilePath, stat.atime, stat.mtime)
Use https://nodejs.org/api/fs.html#fs_fs_copyfile_src_dest_flags_callback .
The documentation does not say it but based on my tests it does keep/set the Modified-time to be the same as in the source-file, at least on Windows-10.
It does set the Created -time to the time the copy was made. But your question is about the modified-time so this is probably the simplest way to get what you want.
BTW. I find it curious that it now seems like the file was modified before it was created. How could that be! But so it seems, at least on Windows 10. I guess that's a good hint for us that the file was copied from somewhere else.
I am new to actionscript and jsfl programming. I am using Adobe Flash Professional CS5.5 and windows 7 operating system. I am trying to execute Javascript API commands in my .as file using the MMExecute() function. When publishing the swf file the statements before and after the 'MMExecute' statement are getting executed but the Javascript command string I am using in the MMExecute function doesn't seem to get executed. I am using a basic JSFL command to just trace to the output window in flash. Also, I am publishing the swf file to the WindowsSwf folder present in the Configuration folder. The fla file I have is a blank file with nothing added to it and the code I am using is as follows.
import flash.display.*;
import flash.text.*;
import flash.external.*;
import adobe.utils.MMExecute;
var str:String=new String();
str='fl.trace("Working..");';
MMExecute(str);
Please help me out.
Thanks in advance.
I'm not a real JS programmer, just an artist who got into JSFL, but:
var str:String=new String();
seems odd to me. I don't typically declare var types in JSFL.
(no idea if that's common or I'm just sloppy.)
I would typically just write
var str='fl.trace("Working..");';
it is also possible you may need to escape the first semicolon.