As my title says, is it possible? I am begginer at front-end and trying to teach myself reactJS right now. I learned some javascript before and I know it is impossible to read or write files with it. Mainly what I want to do is to get string from input and lets say write it into file.
Well the question is, where does that file live?
Node is able to write to files because the files exist on the server that node is running on.
React runs in browser so there is no shared file system to write to. You can read from a file because the contents of that file get bundled into the Javascript that gets served to the browser.
If you want to write to a file, you would need to send an API request from your browser / React to a server and have that server write to the file system.
Additionally, as pointed out by Huy Nguyen, it's possible to write to the clients file system from the browser but that is going to be private to that user.
Your question is a bit vague. In addition to what #Stretch0 said, it's possible to read/write files on a user's computer using the browser's native APIs. Here is a good tutorial.
Related
I have some .sh files, this file contains my ssh and scp details.
I would like to encrypt the ssh files, upon encryption It should be able to execute/run.
like the background.js ( attachment ) file is encrypted but still executing in the browser
Background:
There is a difference between obfuscation and encryption.
Obfuscation hides the data or makes it hard to read, but it is still theoretically possible to reverse this and get back the original source data.
Encryption actually uses cryptography to make it near-impossible to decrypt without a key.
I believe the image I'm looking at above is "obfuscated" and not "encrypted" based on the details that you've provided.
Answer:
If you're running this file on a machine and not in a browser, I'd recommend looking at compiling it into an executable which will compile it into bytecode. This will likely accomplish your original intent of hiding the source. Nexe is one tool for NodeJS that can do this.
If you're running this in the browser, then you can only really obfuscate it. Terser is a library for this in NodeJS
And lastly, a common pattern for hiding ssh details is to put them into environment variables and have a script reference the environment variables rather than actually putting the credentials in the code.
In JS, that would be process.env.PASSWORD
I'm trying to save some screen dumps to internal storage for debugging purposes, but I can't seem to get access to them. When I call FileSystemStorage.getInstance().getAppHomePath(), I get a path that looks something like this:
/data/data/com.mycompany.myapp/files/
But I can't see this folder in the Android File Transfer tool, so I can't drag the files to my Mac. I also tried attaching them to an email using the Message class, but for some reason the attachments never showed up. I notice that a lot of applications store data in folders like this:
/Android/data/com.doubletwist.androidplayer/
If I try to create a folder like this, I run into two problems. First, it's not platform independent. (This doesn't matter much because I'm just doing this for debugging.) Second, it doesn't work. I get an error telling me I need to use the directory returned by FileSystemStorage.getInstance().getAppHomePath()
Is there any way I can save files to a folder that I can actually retrieve them from? It would be more helpful if I had a platform-independent way, but any way that works is fine for now.
File system is a very "unportable" notion. By default app home is a private folder which some mobile OS's including Android 4+ keep private and inaccessible.
Android has a concept of "sdcard" which used to be a physical storage where you could write anything in any directory without a problem. This is no longer applicable for later versions of Android but you can read from the sdcard directory and detect it.
FileSystemStorage has an API to get roots and their types, if you have an sdcard type you can read from there. You can use the FileTree to see the file hierarchy as exposed to your application which can be useful for debugging.
I'm looking for the simplest possible (cross-platform, but not necessarily cross-browser) code to send data from a local web page to a C (not C++) application running locally. Basically, I have an HTML page with a form and I want to send the data from that form to another process in the simplest way possible. (I know that I can read local data from a webpage relatively easily, especially now with HTML5, but writing outside of the javascript sandbox is a mystery.)
I know that browsers make this very hard to do for security concerns, and I don't want to open up my machine to attacks, but maybe I can run a very simple server inside the C application to receive the submitted data... Either way, I cannot run any standard webserver, so I need to have a C library/app that does it for me.
I've looked into .hta files (seem to only work for Windows) and some C web servers (all I've found are *nix specific). A similar question is how to transfer of data from webpage to a server c program , except that user allows the use of Java and other webserver platforms (I must use C).
UPDATE: Promising libraries: https://stackoverflow.com/questions/175507/c-c-web-server-library
Have you considered FastCGI? I have a fast CGI library written in C that might be helpful. It still needs a lot of work and I'm not sure if I would want to use in a production environment.
If you find any bugs or make any enhancements, please share them so that it can help others.
https://github.com/manvscode/shrewd-cgi
You could write a very simple web server in C, serve the page from it (avoids security issues), and post the form to it.
If you're bound to c, you'll have to go low-level and deal with all the nifty details around the sockets library. (There's a reason why people abstract that in high-level languages). Check out some example code for RPC in C with server and client here. If you can afford to bind to C, e.g. using Tcl, i would implement the server in a tcl script and bind your C functions as a Tcl command. That way you pass the content directly to your c method while avoiding to write all the sockets code low-level.
Send the desired data from web to specific port of your system (for example port X). Then run your application (e.g. APP) in background using following command:
nc -l X | ./APP
And of course you need nc package.
I wanted to upload a jpeg image file on the server.I have a GoAhead web server which supports only cgi c program as a serverside handeling.
Can any one know how to handle http posted image file in program witten in cgi in c language?
The GoAhead web server has a file upload filter for this purpose. The upload filter receives the uploaded file and saves it to disk. It then sets some request variables describing the upload. Those variables are accessible via CGI or via action functions or JST templates.
There is an example in test.c. Search for uploadTest().
See: https://github.com/embedthis/goahead/blob/master/test/test.c
To get POST data just read stdin. Environment variable CONTENT_LENGTH tells you how much to expect but of course you need to make your code robust against whatever a potentially malicious user can throw at you.
I'm working on a WinForms C# 3.0 / .NET 3.5 project involving building some canned reports. One of the requirements of the project is to export to PDF format, and currently doing so to disk is working just fine. The question was raised, however, if it's possible to export the file to a stream and open it directly in the native viewer on the client, skipping entirely writing it to disk. I know that this is somewhat possible with ASP.Net through the use of Response.Write() headers and the like, but I need to try to do this with standard WinForms/WPF, and I've exhausted my own ideas for it. Anybody have any insight on how it might be done, if it's possible at all? Or does the file have to be written to disk first, then opened separately?
I think it is important that you ask yourself what you accomplish if you bypass the file system. Writing to a the standard temporary folder is a perfectly acceptable solution. This is typically how browsers let you view media files and pdfs. I would concentrate on writing a nice cleanup function, that removes the temporary file after it has been create. Also what would be the purpose of exporting to PDF if you are not saving the file?
Under Unix / Linux you could have made a named pipe in the file system. This make sense if you have a huge media stream that you want to buffer between applications. In the PDF case you win very little.
Export to a temporary folder. It is Ok.
You will need to write the PDF to a temp directory.
The only way to display a PDF from an in-memory stream is to embed a third-party PDF viewer control