Binary file read javascript

The example above fetches the byte at offset x within the loaded binary data. The valid range for x is from 0 to filestream. See also downloading files. The following example creates a text file on-the-fly and uses the POST method to send the "file" to the server. This example uses plain text, but you can imagine the data being a binary file instead. This is building a byte array of 8-bit integers and sending it; you can use any binary data you'd like, of course.

I don't know if it is the fastest way, but it's as fast as the Windows Calculator in the "Programmer View". Instead of using eval which is not quite safe , you can use your own format alternatively, xml or json for which there are plenty of libs and parse it yourself. Most browser exploit's use this technique for embedding shellcode into HTML pages, it works very well for creating arbitrary binary streams.

Welcome to everyone who found this older post on Google. I figured out a solution that works in Chrome as of , so hopefully this is just some added feature or something most people missed. You can use a 0b prefix to your number.

It won't quite get the binary representation, but you can easily convert it to an integer for storage. For example, you could store the binary number as such:. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Is there a way to read binary data in JavaScript? Ask Question. Asked 13 years, 1 month ago. Active 2 years, 2 months ago. Viewed 78k times. I would like to inject binary data into an object in JavaScript. Is there a way to do this?

Any help would be great. Improve this question. Drew Noakes k gold badges silver badges bronze badges. Add a comment. Active Oldest Votes. Improve this answer. Greg Greg k 52 52 gold badges silver badges bronze badges. Open ; bs. Read; bs. Improve this answer. This is the way to go. The only solution both complete and correct. How could the opposite be done? That is, from a byte array to a variant. Not quite what I wanted, but pretty close. The result I used with success is below. Stream" bs.

ReadText; bs. ReadAllBytes filename ;. How does it work in other locales? Your backward translation seems pre-set. Is it possible to costruct the translation at run-time somehow? Open; binStream.

Recordset" ; RS. This seems to work exactly like FSO File. OpenAsTextStream 1. Stream" bin. Open bin. Sijin Sijin 4, 20 20 silver badges 22 22 bronze badges. The issue is that the thing obtained from bin. Read is not a Javascript byte array. It's an array of variants. To use that code, it's necessary to map from the variant array to a JS byte array. See my code stackoverflow.

An alternative is to replace line 5 with a. Read 1 ; This yields an array of single characters instead of an array of numbers. Ronald Davis Ronald Davis 21 3 3 bronze badges. WriteText source. SetEOS ; memory. Open 'your output path goes here.