commit a70c9b5473f64760c15d65245b08ba5fa0414e66
parent 528829c7f8919c34edae11b46a8582c775fa5882
Author: Henry Wilson <henry@henryandlizzy.uk>
Date: Sun, 21 Dec 2025 19:59:51 +0000
Add ls
Diffstat:
3 files changed, 56 insertions(+), 0 deletions(-)
diff --git a/linux.h b/linux.h
@@ -4,6 +4,8 @@ typedef unsigned long long size_t;
typedef signed long long ssize_t;
typedef unsigned long long uintptr_t;
typedef signed long long intptr_t;
+typedef unsigned long long ino64_t;
+typedef signed long long off64_t;
enum {
AT_FDCWD = -100,
@@ -27,4 +29,14 @@ extern int read(int fd, char* data, size_t count);
extern int write(int fd, char const* data, size_t count);
extern int openat(int fd, char const* name, int flags, int mode);
extern int close(int fd);
+
+struct linux_dirent64 {
+ ino64_t d_ino; /* 64-bit inode number */
+ off64_t d_off; /* Not an offset; see getdents() */
+ unsigned short d_reclen; /* Size of this dirent */
+ unsigned char d_type; /* File type */
+ char d_name[]; /* Filename (null-terminated) */
+};
+extern ssize_t getdents64(int fd, struct linux_dirent64 dirp[], size_t count);
+
extern void* mmap(void* addr, unsigned long len, unsigned long prot, unsigned long flags, unsigned long fd, unsigned long off);
diff --git a/ls.c b/ls.c
@@ -0,0 +1,43 @@
+#include "linux.h"
+
+#define assert(x) if (!(x)) __builtin_trap()
+
+size_t strlen(char const* p)
+{
+ char const* const begin = p;
+ while (*p)
+ ++p;
+
+ return p - begin;
+}
+
+ssize_t wr(int fd, char const* str)
+{
+ return write(fd, str, strlen(str));
+}
+
+int main()
+{
+ int fd = openat(AT_FDCWD, ".", O_RDONLY, 0);
+ assert(fd >= 0);
+
+ struct linux_dirent64 buf[4];
+ for (;;)
+ {
+ ssize_t n = getdents64(fd, buf, sizeof(buf));
+ assert (n >= 0);
+
+ if (!n)
+ break;
+
+ char* const begin = (void*)buf;
+
+ for (ssize_t i = 0; i < n;)
+ {
+ struct linux_dirent64* e = (void*)(begin + i);
+ wr(1, e->d_name);
+ wr(1, "\n");
+ i += e->d_reclen;
+ }
+ }
+}
diff --git a/x86_64.s b/x86_64.s
@@ -47,4 +47,5 @@ _syscall 1 syscall3 write
_syscall 3 syscall3 close
_syscall 9 syscall6 mmap
_syscall 60 syscall3 exit
+_syscall 217 syscall3 getdents64
_syscall 257 syscall6 openat
