4 ms·

I wonder if it’s https://justine.lol/ape.html https://justine.lol/ape.html / cosmopolitan libc

eesmith 2y ago
Shouldn't be. See the "exit 1" in your link? That's the end of the shell script, and as the OpenBSD link says; > It remains possible to put arbitrary bytes AFTER the parts of the shell script that get parsed & executed (like some Solaris patch files do). But you can't put arbirary bytes in the middle,
- oguz-ismail 2y ago
  It is. Binaries generated by cosmocc have NUL in the middle.
  - comex 2y ago
    Ah, indeed. Here are the first 16 bytes of one: 4d 5a 71 46 70 44 3d 27 0a 00 00 10 00 f8 00 00 |MZqFpD='........| There are already nul bytes here, and there are a lot more before the single quote gets closed at offset 0x200.
    - eesmith 2y ago
      And I can confirm a NUL in 11th byte of my hello.c a.out: >>> s[:11] b"MZqFpD='\n\n\x00" Looking closer, I missed the content of "BIOS BOOT SECTOR".
chubot 2y ago
I'm pretty sure it is, I remember reading something about this Yeah I found it here https://news.ycombinator.com/item?id=41030960 https://news.ycombinator.com/item?id=41030960 2019 bug - https://austingroupbugs.net/view.php?id=1250 https://austingroupbugs.net/view.php?id=1250 https://justine.lol/cosmo3/ https://justine.lol/cosmo3/ > This is an idea whose time has come; POSIX even changed their rules about binary in shell scripts specifically to let us do it. FWIW I agree with this OpenBSD change, which says more pointedly All the shells are written in C, and majority of them use C strings for everything, which means they cannot embed a NUL, so this is not surprising. It is quite unbelievable there are people trying to rewrite history on a lark, and expecting the world to follow alone. i.e. it's not worth it to change a bunch of old code in order to allow making code more esoteric. We want systems code to be more predictable, reliable, and less esoteric ... not more esoteric
- asveikau 2y ago
  > POSIX even changed their rules about binary in shell scripts specifically to let us do it. I'd seen this quote around. The fact that the standards were changed to allow it never struck me as a good indication that it should be relied upon. It seems rather backwards of how these standards work. I got flamed on HN once for saying cosmopolitan libc shouldn't be used for production because it relies on weird behaviors and implementation quirks that aren't really an ABI.
  - comex 2y ago
    Looking at this further, the standards change doesn't even match what Cosmopolitan is doing. From the 'changed their rules' link, the 'Desired Action' is to add this text: "The input file may be of any type, but the initial portion of the file intended to be parsed according to the shell grammar [..] shall not contain the NUL character." This handles things like shar archives where you have a shell script at the beginning, then an exit command, then binary gunk. But Cosmopolitan binaries are not just shell scripts with binary. They're hybrids of shell script and DOS executable. And apparently this requires putting nul bytes right near the beginning (see my other comment, https://news.ycombinator.com/item?id=41640331 https://news.ycombinator.com/item?id=41640331), in the "portion [..] intended to be parsed according to the shell grammar". Which explicitly violates the new text. I can understand why this hack is needed for what Cosmopolitan is trying to accomplish, but it makes no sense to claim POSIX blessed it.
    - chubot 2y ago
      Yeah exactly, that was my reading too! The claim in the link doesn't match what the POSIX bug says If it did, then would be a sign that the POSIX process is not working well Because POSIX is supposed to be descriptive of what exists, not prescribe new behavior
      - enriquto 2y ago
        > POSIX is supposed to be descriptive of what exists, not prescribe new behavior Well, it can be argued that ape already existed when that POSIX change was written :) Everything is working as intended. Nothing to see here. Move along. Move along.
tiffanyh 2y ago
Just yesterday I asked @jart, here on HN, about Cosmo & OpenBSD. https://news.ycombinator.com/item?id=41627889 https://news.ycombinator.com/item?id=41627889 APE was mentioned and some interesting tidbits in the GitHub link provided in the HN comment above.

Shouldn't be. See the "exit 1" in your link? That's the end of the shell script, and as the OpenBSD link says; > It remains possible to put arbitrary bytes AFTER the parts of the shell script that get parsed & executed (like some Solaris patch files do). But you can't put arbirary bytes in the middle,

oguz-ismail 2y ago
It is. Binaries generated by cosmocc have NUL in the middle.
- comex 2y ago
  Ah, indeed. Here are the first 16 bytes of one: 4d 5a 71 46 70 44 3d 27 0a 00 00 10 00 f8 00 00 |MZqFpD='........| There are already nul bytes here, and there are a lot more before the single quote gets closed at offset 0x200.
  - eesmith 2y ago
    And I can confirm a NUL in 11th byte of my hello.c a.out: >>> s[:11] b"MZqFpD='\n\n\x00" Looking closer, I missed the content of "BIOS BOOT SECTOR".

chubot 2y ago

I'm pretty sure it is, I remember reading something about this Yeah I found it here https://news.ycombinator.com/item?id=41030960 https://news.ycombinator.com/item?id=41030960 2019 bug - https://austingroupbugs.net/view.php?id=1250 https://austingroupbugs.net/view.php?id=1250 https://justine.lol/cosmo3/ https://justine.lol/cosmo3/ > This is an idea whose time has come; POSIX even changed their rules about binary in shell scripts specifically to let us do it. FWIW I agree with this OpenBSD change, which says more pointedly All the shells are written in C, and majority of them use C strings for everything, which means they cannot embed a NUL, so this is not surprising. It is quite unbelievable there are people trying to rewrite history on a lark, and expecting the world to follow alone. i.e. it's not worth it to change a bunch of old code in order to allow making code more esoteric. We want systems code to be more predictable, reliable, and less esoteric ... not more esoteric

asveikau 2y ago
> POSIX even changed their rules about binary in shell scripts specifically to let us do it. I'd seen this quote around. The fact that the standards were changed to allow it never struck me as a good indication that it should be relied upon. It seems rather backwards of how these standards work. I got flamed on HN once for saying cosmopolitan libc shouldn't be used for production because it relies on weird behaviors and implementation quirks that aren't really an ABI.
- comex 2y ago
  Looking at this further, the standards change doesn't even match what Cosmopolitan is doing. From the 'changed their rules' link, the 'Desired Action' is to add this text: "The input file may be of any type, but the initial portion of the file intended to be parsed according to the shell grammar [..] shall not contain the NUL character." This handles things like shar archives where you have a shell script at the beginning, then an exit command, then binary gunk. But Cosmopolitan binaries are not just shell scripts with binary. They're hybrids of shell script and DOS executable. And apparently this requires putting nul bytes right near the beginning (see my other comment, https://news.ycombinator.com/item?id=41640331 https://news.ycombinator.com/item?id=41640331), in the "portion [..] intended to be parsed according to the shell grammar". Which explicitly violates the new text. I can understand why this hack is needed for what Cosmopolitan is trying to accomplish, but it makes no sense to claim POSIX blessed it.
  - chubot 2y ago
    Yeah exactly, that was my reading too! The claim in the link doesn't match what the POSIX bug says If it did, then would be a sign that the POSIX process is not working well Because POSIX is supposed to be descriptive of what exists, not prescribe new behavior
    - enriquto 2y ago
      > POSIX is supposed to be descriptive of what exists, not prescribe new behavior Well, it can be argued that ape already existed when that POSIX change was written :) Everything is working as intended. Nothing to see here. Move along. Move along.

tiffanyh 2y ago

Just yesterday I asked @jart, here on HN, about Cosmo & OpenBSD. https://news.ycombinator.com/item?id=41627889 https://news.ycombinator.com/item?id=41627889 APE was mentioned and some interesting tidbits in the GitHub link provided in the HN comment above.