Perl updating a file in place
This article will show you one way to verify the file's contents: checking its 32-bit CRC value.View page [...] This is an old article, and sadly this is still a problem today.Whether it happened through hardware failure, program error, or malicious tampering, I like to know when a file has had its contents altered.
This method is still doable today, is very very fast, and has little or no consequences to the use of devices other than prohibiting the cut/paste of binary files.The strings indicated CRC and other characteristics of the file.Any time the actual characteristics did not match the embedded hashed characteristics, a flag was raised with a notice of a mismatch and likely invalidation of the file. This was not popular for a variety of reasons, almost universally with the same root - a motive to cut/paste the binary file without replacing it and without notifying the owner or user of the device.I didn’t learn web programming at university, I didn’t pay for a course in j Query or PHP – I just started making websites one day, and ended up here.I made this 15 years ago as an experiment in auto-generating HTML files from a structured directory of plain text files, using Perl programming. Seriously, this was the height of cool at the time.
Now, that said, file verification is only one of a large array of challenges involved in securing a device.