user: 请将这段汇编代码片段转换成等效的C代码:

```asm
<main>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0xf8,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0xe8(%rsp)
  xor    %eax,%eax
  movl   $0x5,0xc(%rsp)
  lea    D38(%rip),%rdi
  call   <printf@plt>
  lea    0x10(%rsp),%rsi
  lea    D115(%rip),%rdi
  mov    $0x0,%eax
  call   <scanf@plt>
  cmpb   $0x0,0x10(%rsp)
  je     L68
  mov    $0x1,%eax
  lea    0xf(%rsp),%rdx
L79:
  mov    %eax,%ebp
  add    $0x1,%rax
  cmpb   $0x0,(%rdx,%rax,1)
  jne    L79
L52:
  mov    %ebp,%esi
  lea    D125(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  cmpl   $0x5,0xc(%rsp)
  jne    L86
  lea    D6(%rip),%r14
  lea    D126(%rip),%r13
  lea    D23(%rip),%r12
  lea    D118(%rip),%rbx
  jmp    L49
L68:
  mov    $0x0,%ebp
  jmp    L52
L140:
  cmp    $0x4,%eax
  jne    L158
  lea    D16(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    0x80(%rsp),%r15
  mov    %r15,%rsi
  lea    D115(%rip),%rdi
  mov    $0x0,%eax
  call   <scanf@plt>
  lea    0x10(%rsp),%rdi
  mov    %ebp,%edx
  mov    %r15,%rsi
  call   <concat@plt>
  jmp    L145
L16:
  lea    0x10(%rsp),%rdi
  call   <copy@plt>
L145:
  lea    D86(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    0xc(%rsp),%rsi
  mov    %rbx,%rdi
  mov    $0x0,%eax
  call   <scanf@plt>
  cmpl   $0x5,0xc(%rsp)
  jne    L86
L49:
  mov    %r14,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  mov    %r13,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  mov    %r12,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    D41(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    D18(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    0x8(%rsp),%rsi
  mov    %rbx,%rdi
  mov    $0x0,%eax
  call   <scanf@plt>
  mov    0x8(%rsp),%eax
  cmp    $0x3,%eax
  je     L127
  jg     L140
  cmp    $0x1,%eax
  je     L16
  cmp    $0x2,%eax
  jne    L158
  lea    0x10(%rsp),%rdi
  mov    %ebp,%esi
  call   <rev@plt>
  jmp    L145
L127:
  lea    0x10(%rsp),%rdi
  mov    %ebp,%esi
  call   <pal@plt>
  jmp    L145
L158:
  lea    D11(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  jmp    L145
L86:
  mov    0xe8(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L94
  mov    $0x0,%eax
  add    $0xf8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L94:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: parse_data
arguments: data_label: D38
type_guessed: string
name: parse_data
arguments: data_label: D115
type_guessed: string
name: parse_data
arguments: data_label: D125
type_guessed: string
name: parse_data
arguments: data_label: D6
type_guessed: string
name: parse_data
arguments: data_label: D126
type_guessed: string
name: parse_data
arguments: data_label: D23
type_guessed: string
name: parse_data
arguments: data_label: D118
type_guessed: string
name: parse_data
arguments: data_label: D16
type_guessed: string
name: parse_data
arguments: data_label: D86
type_guessed: string
name: parse_data
arguments: data_label: D41
type_guessed: string
name: parse_data
arguments: data_label: D18
type_guessed: string
name: parse_data
arguments: data_label: D11
type_guessed: string

tool: D38: 
Enter string s1: 

tool: D115: %s

tool: D125: Length of string: %d


tool: D6: 
1) To copy a string

tool: D126: 
2) To reverse a string

tool: D23: 
3) To find whether it is palindrome or not

tool: D118: %d

tool: D16: Enter second string: 

tool: D86: 
Enter 5 to continue, else exit: 

tool: D41: 
4) To concatenate two strings

tool: D18: 
Enter 1,2,3 or 4: 

tool: D11: 
Invalid Choice

assistant: ```c
int main() {
  char s1[100], s2[100];
  int choice, len, ans = 5;
  printf("\nEnter string s1: ");
  scanf("%s", s1);
  for (len = 0; s1[len] != '\0'; ++len)
    ;
  printf("Length of string: %d\n", len);
  while (ans == 5) {
    printf("\n1) To copy a string");
    printf("\n2) To reverse a string");
    printf("\n3) To find whether it is palindrome or not");
    printf("\n4) To concatenate two strings");
    printf("\nEnter 1,2,3 or 4: ");
    scanf("%d", &choice);
    switch (choice) {
    case 1:
      copy(s1);
      break;
    case 2:
      rev(s1, len);
      break;
    case 3:
      pal(s1, len);
      break;
    case 4:
      printf("Enter second string: ");
      scanf("%s", s2);
      concat(s1, s2, len);
      break;
    default:
      printf("\nInvalid Choice");
    }
    printf("\nEnter 5 to continue, else exit: ");
    scanf("%d", &ans);
  }
  return 0;
}
```