6 ms·

Claude has surprisingly good knowledge of X11 protocol. The other day, colleague showed me a (pretty basic) terminal emulator written in one-shot by Opus. Kick

by kees99 2mo ago

Claude has surprisingly good knowledge of X11 protocol. The other day, colleague showed me a (pretty basic) terminal emulator written in one-shot by Opus. Kicker is - that was compiled to a 30 KB static binary. That's right. No libX11, no libXfont, not even libc.

glitchc 2mo ago
No libc? It used inline assembly routines?
- kees99 2mo ago
  Yes, something like this: static inline long read(int fd, void *buf, long count) { register long rax asm("rax") = __NR_read; register long rdi asm("rdi") = (long)fd; register long rsi asm("rsi") = (long)buf; register long rdx asm("rdx") = count; asm volatile( "syscall" : "+r"(rax) : "r"(rdi), "r"(rsi), "r"(rdx) : "rcx", "r11", "memory" ); return rax; }
  - asveikau 2mo ago
    The linux kernel also has its own headers (IIRC it was something like <asm/unistd.h> and/or <sys/syscall.h>, but might depend on architecture and version) where it will provide the stub asm statements. In my memory the syscall ABI has changed a few times (i386 had int $0x80, then sysenter, then abstracting it in the vdso, then amd64 has 'syscall'), so it may be easier to let the kernel header provide the mechanism.
    - yjftsjthsd-h 2mo ago
      The Linux syscall ABI is (famously) stable; on x86* you can still call into 0x80 just fine. There might be new interfaces made available, but existing programs shouldn't break. Although, in C there could be value in abstracting over the per-platform differences like int/syscall. I've only ever done raw syscalls from assembly where portability was rather moot:)
- Chu4eeno 2mo ago
  It's quite easy to get it to do syscalls directly, I even got Fable to do a simple standalone TLS implementation (in C). Not really useful since it hardcoded a set of supported algorithms etc., but it's fun to see how "simple" you can force it to go.
amszmidt 2mo ago
Only because the X Window System is very heavily documented, e.g., in the excellent "The Definitive Guides to the X Window System Series".
vidarh 2mo ago
Yeah, I've had it work on an X11 server using a Ruby X11 protocol implementation instead of libX11, and it just rushed ahead and added support for a bunch of missing requests and responses. None of that is hard - it's all very well documented - but it's tedious. My terminal emulator using the same binding also started out hand-written but Claude overhauled that too recently and it knows vtxx escape codes far better than me too.
- JCattheATM 2mo ago
  You wrote your own terminal emulator?

by kees99 2mo ago

glitchc 2mo ago

No libc? It used inline assembly routines?

kees99 2mo ago
Yes, something like this: static inline long read(int fd, void *buf, long count) { register long rax asm("rax") = __NR_read; register long rdi asm("rdi") = (long)fd; register long rsi asm("rsi") = (long)buf; register long rdx asm("rdx") = count; asm volatile( "syscall" : "+r"(rax) : "r"(rdi), "r"(rsi), "r"(rdx) : "rcx", "r11", "memory" ); return rax; }
- asveikau 2mo ago
  The linux kernel also has its own headers (IIRC it was something like <asm/unistd.h> and/or <sys/syscall.h>, but might depend on architecture and version) where it will provide the stub asm statements. In my memory the syscall ABI has changed a few times (i386 had int $0x80, then sysenter, then abstracting it in the vdso, then amd64 has 'syscall'), so it may be easier to let the kernel header provide the mechanism.
  - yjftsjthsd-h 2mo ago
    The Linux syscall ABI is (famously) stable; on x86* you can still call into 0x80 just fine. There might be new interfaces made available, but existing programs shouldn't break. Although, in C there could be value in abstracting over the per-platform differences like int/syscall. I've only ever done raw syscalls from assembly where portability was rather moot:)
Chu4eeno 2mo ago
It's quite easy to get it to do syscalls directly, I even got Fable to do a simple standalone TLS implementation (in C). Not really useful since it hardcoded a set of supported algorithms etc., but it's fun to see how "simple" you can force it to go.

amszmidt 2mo ago

Only because the X Window System is very heavily documented, e.g., in the excellent "The Definitive Guides to the X Window System Series".

vidarh 2mo ago

Yeah, I've had it work on an X11 server using a Ruby X11 protocol implementation instead of libX11, and it just rushed ahead and added support for a bunch of missing requests and responses. None of that is hard - it's all very well documented - but it's tedious. My terminal emulator using the same binding also started out hand-written but Claude overhauled that too recently and it knows vtxx escape codes far better than me too.

JCattheATM 2mo ago
You wrote your own terminal emulator?