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

```asm
<getop>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x20,%rsp
  mov    %rdi,-0x18(%rbp)
  nop
L151:
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %al,-0x9(%rbp)
  mov    -0x18(%rbp),%rax
  movzbl -0x9(%rbp),%edx
  mov    %dl,(%rax)
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x20,%al
  je     L151
  cmpb   $0x9,-0x9(%rbp)
  je     L151
  mov    -0x18(%rbp),%rax
  add    $0x1,%rax
  movb   $0x0,(%rax)
  movq   $0x0,-0x8(%rbp)
  movsbl -0x9(%rbp),%eax
  mov    %eax,%edi
  call   <isalpha@plt>
  test   %rax,%rax
  je     L163
  nop
L40:
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %al,-0x9(%rbp)
  addq   $0x1,-0x8(%rbp)
  mov    -0x18(%rbp),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movzbl -0x9(%rbp),%edx
  mov    %dl,(%rax)
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isalpha@plt>
  test   %rax,%rax
  jne    L40
  mov    -0x18(%rbp),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movb   $0x0,(%rax)
  mov    D11(%rip),%rax
  movzbl (%rax),%eax
  cmp    %al,-0x9(%rbp)
  je     L156
  movsbl -0x9(%rbp),%eax
  mov    %eax,%edi
  call   <ungetch@plt>
L156:
  mov    -0x18(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  cmp    $0x1,%eax
  jle    L125
  mov    $0x6e,%eax
  jmp    L35
L125:
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  jmp    L35
L163:
  movsbl -0x9(%rbp),%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L184
  cmpb   $0x2e,-0x9(%rbp)
  je     L184
  cmpb   $0x2d,-0x9(%rbp)
  je     L184
  movzbl -0x9(%rbp),%eax
  jmp    L35
L184:
  cmpb   $0x2d,-0x9(%rbp)
  jne    L153
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %al,-0x9(%rbp)
  movsbl -0x9(%rbp),%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L53
  cmpb   $0x2e,-0x9(%rbp)
  jne    L30
L53:
  addq   $0x1,-0x8(%rbp)
  mov    -0x18(%rbp),%rdx
  mov    -0x8(%rbp),%rax
  add    %rax,%rdx
  movzbl -0x9(%rbp),%eax
  mov    %al,(%rdx)
  jmp    L153
L30:
  mov    D11(%rip),%rax
  movzbl (%rax),%eax
  cmp    %al,-0x9(%rbp)
  je     L135
  movsbl -0x9(%rbp),%eax
  mov    %eax,%edi
  call   <ungetch@plt>
L135:
  mov    $0x2d,%eax
  jmp    L35
L153:
  movsbl -0x9(%rbp),%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  je     L165
  nop
L174:
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %al,-0x9(%rbp)
  addq   $0x1,-0x8(%rbp)
  mov    -0x18(%rbp),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movzbl -0x9(%rbp),%edx
  mov    %dl,(%rax)
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L174
L165:
  cmpb   $0x2e,-0x9(%rbp)
  jne    L5
  nop
L89:
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %al,-0x9(%rbp)
  addq   $0x1,-0x8(%rbp)
  mov    -0x18(%rbp),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movzbl -0x9(%rbp),%edx
  mov    %dl,(%rax)
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L89
L5:
  mov    -0x18(%rbp),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movb   $0x0,(%rax)
  mov    D11(%rip),%rax
  movzbl (%rax),%eax
  cmp    %al,-0x9(%rbp)
  je     L98
  movsbl -0x9(%rbp),%eax
  mov    %eax,%edi
  call   <ungetch@plt>
L98:
  mov    $0x30,%eax
L35:
  leave
  ret
```

assistant: ```c
char getop(char s[]) {
  size_t i;
  char c;
  while ((s[0] = c = getch()) == ' ' || c == '\t')
    ;
  s[1] = '\0';
  i = 0;
  if (isalpha(c)) {
    while (isalpha(s[++i] = c = getch()))
      ;
    s[i] = '\0';
    if (c != EOF)
      ungetch(c);
    if (strlen(s) > 1)
      return 'n';
    else
      return s[0];
  }
  if (!isdigit(c) && c != '.' && c != '-')
    return c;
  if (c == '-') {
    if (isdigit(c = getch()) || c == '.')
      s[++i] = c;
    else {
      if (c != (char)EOF)
        ungetch(c);
      return '-';
    }
  }
  if (isdigit(c))
    while (isdigit(s[++i] = c = getch()))
      ;
  if (c == '.')
    while (isdigit(s[++i] = c = getch()))
      ;
  s[i] = '\0';
  if (c != (char)EOF)
    ungetch(c);
  return '0';
}
```