cheatsheets devlog projects

filepeek.md

Filepeek

2022-11-04 1

As part of the efforts to view and clear replication bits on UniVerse 10.3.6 we also found the program called filepeek. It is a Linux utility provided by rocket that gives you a REPL like environment to interact with UniVerse files. You will need to be root to be able to use it.

You can do filepeek FILE.NAME on a universe file and this will put you inside the file. You can then type in a hex address to go to that byte and view it.

SW 20 - This command will let you set the window size to 32 bytes, which will display 2 lines. SW expects the number to be a multiple of 32 and in hexadecimal format. So the min is 20 which is 2 lines, 40 will display 4 lines, 60 will display 6 lines.

228 - This will take you to byte 552 which is 228 in hex.

W 228 = 1 - This will write the hex value 1 to the byte 0x228. This will get written out immediately.

Q - This will let you exit the program.

Filepeek is a useful program to quickly check various bits of a UniVerse file. In our case, for replication we want to look at the bytes 0x228 which is the flag for publishing and the byte 0x22C which holds a key relevant to replication.