Top 4 cpio Open-Source Projects

libarchive

33 2,870 8.8 C

Multi-format archive and compression library

Project mention: The XZ attack and timeline | dev.to | 2024-04-17

29. October 2021 At this point Jia Tan pops up, and the first thing we see from him is an innocuous patch to the xz repository, and while a lot of people believe he started out trying his luck with another library also known as libarchive, this is not the case, I would bet it’s more of a backup looking at the dates, being that there are a few days in between as shown in this commit.

fpart

5 215 7.9 C

Sort files and pack them into partitions
InfluxDB

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metatar

1 31 6.2 Go

Manipulate tar file metadata, list tar files or convert tar to cpio. For some projects, this can replace fakeroot and cpio, when creating an initrd image that is compatible with the Linux kernel. Used in production in at least one company.
pycpio

1 3 8.4 Python

Python library for CPIO manipulation

Project mention: Build Initramfs Rootless | news.ycombinator.com | 2024-03-08

You can't make them on the filesystem itself, gen_init_cpio lets you specify device nodes to be created within the archive, but they are not actually created on the live system and do not require privileges.
I made my own CPIO library: https://github.com/desultory/pycpio and one of the main goals was this behavior, so I could create CPIO archives with device nodes without privileges. It's really as simple as writing some bytes to a file saying "when you extract this, create this device node". It's not like any archive actually has a device node, just instructions for where to put them, and what properties they have.
Certainly, you can't extract these archives as non-root, but you have to go out of your way to make an initramfs have non-root privileges.

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020).