user: Please show me the C implementation that matches the assembly code listed below:

```asm
<expandpath>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %rbx
  sub    $0x1000,%rsp
  orq    $0x0,(%rsp)
  sub    $0x48,%rsp
  mov    %rdi,-0x1048(%rbp)
  mov    %esi,-0x104c(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x18(%rbp)
  xor    %eax,%eax
  movq   $0x0,-0x1030(%rbp)
  movq   $0x0,-0x1028(%rbp)
  movl   $0x0,-0x1034(%rbp)
  mov    -0x1048(%rbp),%rax
  movzbl (%rax),%eax
  mov    %al,-0x1037(%rbp)
  mov    -0x1048(%rbp),%rax
  movzbl 0x1(%rax),%eax
  mov    %al,-0x1036(%rbp)
  mov    -0x1048(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  cltq
  lea    -0x1(%rax),%rdx
  mov    -0x1048(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  mov    %al,-0x1035(%rbp)
  cmpb   $0x2f,-0x1035(%rbp)
  jne    L59
  cmpl   $0x0,-0x104c(%rbp)
  je     L59
  mov    $0x0,%eax
  jmp    L43
L59:
  cmpb   $0x7e,-0x1037(%rbp)
  je     L34
  cmpb   $0x2f,-0x1037(%rbp)
  je     L34
  cmpb   $0x2e,-0x1037(%rbp)
  jne    L212
  cmpb   $0x2f,-0x1036(%rbp)
  je     L34
L212:
  mov    -0x1048(%rbp),%rax
  mov    $0x2f,%esi
  mov    %rax,%rdi
  call   <strchr@plt>
  test   %eax,%eax
  jne    L34
  lea    -0x1020(%rbp),%rax
  mov    $0x1000,%esi
  mov    %rax,%rdi
  call   <getcwd@plt>
  test   %rax,%rax
  je     L34
  lea    -0x1020(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %eax,%ebx
  mov    -0x1048(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  add    %ebx,%eax
  add    $0x2,%eax
  mov    %eax,-0x1034(%rbp)
  mov    -0x1034(%rbp),%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,-0x1028(%rbp)
  cmpq   $0x0,-0x1028(%rbp)
  je     L34
  mov    -0x1048(%rbp),%rcx
  lea    -0x1020(%rbp),%rdx
  mov    -0x1028(%rbp),%rax
  lea    D17(%rip),%rsi
  mov    %rax,%rdi
  call   <sprintf@plt>
  mov    -0x1028(%rbp),%rax
  jmp    L43
L34:
  cmpb   $0x7e,-0x1037(%rbp)
  je     L10
  cmpb   $0x2e,-0x1037(%rbp)
  jne    L199
L10:
  cmpb   $0x2f,-0x1036(%rbp)
  jne    L199
  cmpb   $0x7e,-0x1037(%rbp)
  jne    L169
  mov    $0x0,%eax
  call   <getudir@plt>
  mov    %rax,-0x1030(%rbp)
  jmp    L243
L169:
  lea    -0x1020(%rbp),%rax
  mov    $0x1000,%esi
  mov    %rax,%rdi
  call   <getcwd@plt>
  mov    %rax,-0x1030(%rbp)
L243:
  cmpq   $0x0,-0x1030(%rbp)
  je     L35
  mov    -0x1030(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  cmp    $0x1000,%eax
  jle    L250
  mov    $0x0,%eax
  jmp    L43
L250:
  mov    -0x1030(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %eax,%ebx
  mov    -0x1048(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  add    %ebx,%eax
  mov    %eax,-0x1034(%rbp)
  mov    -0x1034(%rbp),%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,-0x1028(%rbp)
  cmpq   $0x0,-0x1028(%rbp)
  je     L35
  mov    -0x1048(%rbp),%rax
  lea    0x1(%rax),%rcx
  mov    -0x1030(%rbp),%rdx
  mov    -0x1028(%rbp),%rax
  lea    D0(%rip),%rsi
  mov    %rax,%rdi
  call   <sprintf@plt>
  mov    -0x1028(%rbp),%rax
  jmp    L43
L199:
  cmpb   $0x2f,-0x1037(%rbp)
  jne    L245
  mov    -0x1048(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  add    $0x1,%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,-0x1028(%rbp)
  cmpq   $0x0,-0x1028(%rbp)
  je     L245
  mov    -0x1048(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  cmp    $0x1000,%eax
  jg     L245
  mov    -0x1048(%rbp),%rdx
  mov    -0x1028(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcpy@plt>
  jmp    L43
L35:
  nop
L245:
  mov    $0x0,%eax
L43:
  mov    -0x18(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L119
  call   <__stack_chk_fail@plt>
L119:
  mov    -0x8(%rbp),%rbx
  leave
  ret
```

tool_calls: name: retrieve_data
arguments: tag: D17
data_type: string
name: retrieve_data
arguments: tag: D0
data_type: string

tool: D17: %s/%s

tool: D0: %s%s

assistant: ```c
char *expandpath(char *path, int isfile) {
  char firstchar, secondchar, lastchar;
  char cwd[4096];
  char *dir = NULL;
  char *heap = NULL;
  int len = 0;
  firstchar = *path;
  secondchar = *(path + 1);
  lastchar = *(path + strlen(path) - 1);
  if (lastchar == '/' && isfile)
    return NULL;
  if (firstchar != '~' && firstchar != '/') {
    if (!(firstchar == '.' && secondchar == '/')) {
      if (!strchr(path, '/')) {
        if (getcwd(cwd, 4096)) {
          len = strlen(cwd) + strlen(path) + 2;
          if ((heap = malloc(len * sizeof(char)))) {
            sprintf(heap, "%s/%s", cwd, path);
            return heap;
          }
        }
      }
    }
  }
  if ((firstchar == '~' || firstchar == '.') && secondchar == '/') {
    if (firstchar == '~') {
      dir = getudir();
    } else {
      dir = getcwd(cwd, 4096);
    }
    if (dir) {
      if (strlen(dir) > 4096)
        return NULL;
      len = strlen(dir) + strlen(path);
      if ((heap = malloc(len * sizeof(char)))) {
        sprintf(heap, "%s%s", dir, path + 1);
        return heap;
      }
    }
  } else if (firstchar == '/') {
    heap = malloc((strlen(path) + 1) * sizeof(char));
    if (heap)
      if (strlen(path) <= 4096)
        return strcpy(heap, path);
  }
  return NULL;
}
```