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sprintf working! (but not snprintf ...)

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This commit is contained in:
pommicket 2022-02-13 22:12:44 -05:00
parent 2fef698195
commit b9fd2a2b9c
7 changed files with 1724 additions and 65 deletions
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52
05/main.c
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@ -1,50 +1,10 @@
static unsigned char __syscall_data[] = {
// mov rax, [rsp+24]
0x48, 0x8b, 0x84, 0x24, 24, 0, 0, 0,
// mov rdi, rax
0x48, 0x89, 0xc7,
// mov rax, [rsp+32]
0x48, 0x8b, 0x84, 0x24, 32, 0, 0, 0,
// mov rsi, rax
0x48, 0x89, 0xc6,
// mov rax, [rsp+40]
0x48, 0x8b, 0x84, 0x24, 40, 0, 0, 0,
// mov rdx, rax
0x48, 0x89, 0xc2,
// mov rax, [rsp+48]
0x48, 0x8b, 0x84, 0x24, 48, 0, 0, 0,
// mov r10, rax
0x49, 0x89, 0xc2,
// mov rax, [rsp+56]
0x48, 0x8b, 0x84, 0x24, 56, 0, 0, 0,
// mov r8, rax
0x49, 0x89, 0xc0,
// mov rax, [rsp+64]
0x48, 0x8b, 0x84, 0x24, 64, 0, 0, 0,
// mov r9, rax
0x49, 0x89, 0xc1,
// mov rax, [rsp+16]
0x48, 0x8b, 0x84, 0x24, 16, 0, 0, 0,
// syscall
0x0f, 0x05,
// mov [rsp+8], rax
0x48, 0x89, 0x84, 0x24, 8, 0, 0, 0,
// ret
0xc3
};
#define __syscall(no, arg1, arg2, arg3, arg4, arg5, arg6)\
(((unsigned long (*)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long))__syscall_data)\
(no, arg1, arg2, arg3, arg4, arg5, arg6))
typedef unsigned long size_t;
long write(int fd, void *buf, size_t count) {
__syscall(1, fd, buf, count, 0, 0, 0);
}
#include <stdio.h>
int main(int argc, char **argv) {
write(1, "Hello, world!\n", 14);
return 0;
char buf[200] = {0};
sprintf(buf, "Hello, %d %.2f %g %s %p\n", 187, 77.3, 349e12, "Wow!", "yea");
// snprintf(buf, 200, "Hello\n"); //<- NOT WORKING
write(1, buf, sizeof buf);
return *buf;
}