user: What is the c source code of the assembly code below:

```asm
<cmd_line_cd>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x148,%rsp
  mov    %rdi,-0x168(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  mov    %rsp,%rax
  mov    %rax,%rbx
  mov    -0x168(%rbp),%rax
  lea    D20(%rip),%rdx
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcmp@plt>
  test   %rax,%rax
  jne    L19
  lea    D49(%rip),%rax
  mov    %rax,%rdi
  call   <puts@plt>
  jmp    L3
L19:
  mov    -0x168(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  add    $0x1,%rax
  lea    -0x1(%rax),%rdx
  mov    %rdx,-0x160(%rbp)
  mov    %rax,%rdx
  mov    %rdx,%r14
  mov    $0x0,%r15d
  mov    %rax,%rdx
  mov    %rdx,%r12
  mov    $0x0,%r13d
  mov    %rax,%rdx
  mov    $0x10,%eax
  sub    $0x1,%rax
  add    %rdx,%rax
  mov    $0x10,%ecx
  mov    $0x0,%edx
  div    %rcx
  imul   $0x10,%rax,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffff000,%rcx
  mov    %rsp,%rdx
  sub    %rcx,%rdx
L92:
  cmp    %rdx,%rsp
  je     L68
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L92
L68:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L127
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L127:
  mov    %rsp,%rax
  add    $0x0,%rax
  mov    %rax,-0x158(%rbp)
  mov    -0x168(%rbp),%rdx
  mov    -0x158(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcpy@plt>
  mov    -0x158(%rbp),%rax
  lea    D26(%rip),%rdx
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strtok@plt>
  mov    %rax,-0x150(%rbp)
  mov    -0x150(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  je     L100
  mov    -0x150(%rbp),%rax
  lea    D61(%rip),%rdx
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcmp@plt>
  test   %rax,%rax
  jne    L44
L100:
  lea    D61(%rip),%rax
  mov    %rax,%rdi
  call   <set_cur_path@plt>
  jmp    L3
L44:
  lea    -0x140(%rbp),%rdx
  mov    -0x150(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <get_abs_path@plt>
  movzbl -0x140(%rbp),%eax
  test   %al,%al
  jne    L13
  lea    D28(%rip),%rax
  mov    %rax,%rdi
  call   <puts@plt>
  jmp    L3
L13:
  lea    -0x140(%rbp),%rax
  mov    $0x3,%esi
  mov    %rax,%rdi
  call   <iso_dopen@plt>
  mov    %rax,-0x148(%rbp)
  cmpq   $0x0,-0x148(%rbp)
  jne    L37
  lea    -0x140(%rbp),%rax
  mov    %rax,%rsi
  lea    D0(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  jmp    L120
L37:
  lea    -0x140(%rbp),%rax
  mov    %rax,%rdi
  call   <set_cur_path@plt>
L120:
  mov    -0x148(%rbp),%rax
  mov    %rax,%rdi
  call   <iso_dclose@plt>
  nop
L3:
  mov    %rbx,%rsp
  mov    -0x38(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L29
  call   <__stack_chk_fail@plt>
L29:
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

tool_calls: name: read_data
arguments: data_label: D20
type_infered: string
name: read_data
arguments: data_label: D49
type_infered: string
name: read_data
arguments: data_label: D26
type_infered: string
name: read_data
arguments: data_label: D61
type_infered: string
name: read_data
arguments: data_label: D28
type_infered: string
name: read_data
arguments: data_label: D0
type_infered: string

tool: D20: --HELP

tool: D49: Change the current working directory
usage: cd <directory path>

tool: D26:  

tool: D61: /

tool: D28: cd: root has no parent

tool: D0: cd: no such path %s


assistant: ```c
void cmd_line_cd(const char *arg_line) {
  if (strcmp(arg_line, "--HELP") == 0) {
    printf("Change the current working directory\nusage: cd <directory path>\n");
    return;
  }
  char line_copy[strlen(arg_line) + 1];
  strcpy(line_copy, arg_line);
  char *first_word = strtok(line_copy, " ");
  if (strlen(first_word) == 0 || strcmp(first_word, "/") == 0) {
    set_cur_path("/");
    return;
  }
  char abs_path[256];
  get_abs_path(first_word, abs_path);
  if (!abs_path[0]) {
    printf("cd: root has no parent\n");
    return;
  }
  struct iso_dir *dir = iso_dopen(abs_path, 3);
  if (!dir) {
    printf("cd: no such path %s\n", abs_path);
  } else {
    set_cur_path(abs_path);
  }
  iso_dclose(dir);
  return;
}
```