I did something similar with TCL, the basis was using an extension I wrote to handle the UNIX stuff [0]. It operated an On-Premises cloud environment appliance, and `init` was just a TCL script (at one point it was a statically linked binary with the init script embedded, but that turned out to be overkill)
Reading the code, I was surprised to see that cd was implemented by calling out to the os library. I assumed that was something the shell or at least userspace handled. At what level does the concept of a “current directory” exist?
It's at the kernel level. Each process has its own current working directory. On Linux, these CWD values are exposed at `/proc/[...]/cwd`. This value affects the resolution of relative paths in filesystem operations at a syscall level.
Very cool. Good use of quickjs, although it would have been cool if it somehow didn’t need a libc and just used the syscall interface. Makes me want to give that a try.
We’re roughly on schedule. https://www.destroyallsoftware.com/talks/the-birth-and-death...
I did something similar with TCL, the basis was using an extension I wrote to handle the UNIX stuff [0]. It operated an On-Premises cloud environment appliance, and `init` was just a TCL script (at one point it was a statically linked binary with the init script embedded, but that turned out to be overkill)
[0] https://chiselapp.com/user/rkeene/repository/tuapi/doc/trunk...
Check out this:
https://bellard.org/jslinux/vm.html?url=alpine-x86.cfg&mem=1...
and
https://bellard.org/jslinux/
By the famous Fabrice Bellard who is the creator of QuickJS, QEMU, FFMPEG and many other brilliant and fascinating tools!
https://bellard.org/
A very timely endeavor indeed https://devblogs.microsoft.com/typescript/typescript-native-...
Kernighan and Ritchie wept. (Tears of joy at an awesome hack, or tears of sadness at an awesome hack?)
It’s never early to prepare for JavaScript complete takeover.
Reading the code, I was surprised to see that cd was implemented by calling out to the os library. I assumed that was something the shell or at least userspace handled. At what level does the concept of a “current directory” exist?
It's at the kernel level. Each process has its own current working directory. On Linux, these CWD values are exposed at `/proc/[...]/cwd`. This value affects the resolution of relative paths in filesystem operations at a syscall level.
In the kernel’s process structure. See NOTES - https://man7.org/linux/man-pages/man2/chdir.2.html
Unix defines a Working Directory that every process has, changed with chdir(2): https://man7.org/linux/man-pages/man2/chdir.2.html
Very cool. Good use of quickjs, although it would have been cool if it somehow didn’t need a libc and just used the syscall interface. Makes me want to give that a try.