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

```asm
<fftrec>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x68,%rsp
  mov    (%rsi),%r13d
  mov    %fs:0x28,%rax
  mov    %rax,0x58(%rsp)
  xor    %eax,%eax
  test   %r13d,%r13d
  jg     L139
  mov    %rdi,%rbp
  mov    %rsi,%rbx
  call   <strlen@plt>
  cmp    $0x8,%rax
  jbe    L139
  mov    $0x8,%ecx
  jmp    L169
  cs nopw 0x0(%rax,%rax,1)
L42:
  add    $0x1,%rcx
  cmp    %rcx,%rax
  je     L139
L169:
  movsbl 0x0(%rbp,%rcx,1),%r8d
  lea    0x0(%rbp,%rcx,1),%r12
  lea    -0x20(%r8),%edx
  cmp    $0x5e,%dl
  jbe    L42
  mov    %rsp,%r13
  add    $0x1,%ecx
  mov    $0x51,%esi
  lea    D35(%rip),%rdx
  mov    %r13,%rdi
  call   <snprintf@plt>
  movzbl (%r12),%eax
  test   %al,%al
  je     L9
  cmp    $0x1b,%al
  jg     L39
  cmp    $0x8,%al
  jle    L137
  sub    $0x9,%eax
  cmp    $0x12,%al
  ja     L137
  lea    D50(%rip),%rdx
  movzbl %al,%eax
  movslq (%rdx,%rax,4),%rax
  add    %rdx,%rax
  notrack jmp *%rax
  nopl   0x0(%rax,%rax,1)
L9:
  lea    D78(%rip),%rsi
  mov    %r13,%rdi
  call   <strcat@plt>
  nop
L137:
  mov    %r13,%rdi
  call   <ffpmsg@plt>
  mov    %r13,%rdi
  mov    $0x50,%edx
  mov    %rbp,%rsi
  call   <strncpy@plt>
  mov    %r13,%rdi
  movb   $0x0,0x50(%rsp)
  mov    $0xcf,%r13d
  call   <ffpmsg@plt>
  movl   $0xcf,(%rbx)
L139:
  mov    0x58(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L45
  add    $0x68,%rsp
  mov    %r13d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
L39:
  cmp    $0x7f,%al
  jne    L137
  lea    D88(%rip),%rsi
  mov    %r13,%rdi
  call   <strcat@plt>
  jmp    L137
  lea    D71(%rip),%rsi
  mov    %r13,%rdi
  call   <strcat@plt>
  jmp    L137
  lea    D18(%rip),%rsi
  mov    %r13,%rdi
  call   <strcat@plt>
  jmp    L137
  lea    D19(%rip),%rsi
  mov    %r13,%rdi
  call   <strcat@plt>
  jmp    L137
  lea    D73(%rip),%rsi
  mov    %r13,%rdi
  call   <strcat@plt>
  jmp    L137
  lea    D31(%rip),%rsi
  mov    %r13,%rdi
  call   <strcat@plt>
  jmp    L137
  lea    D2(%rip),%rsi
  mov    %r13,%rdi
  call   <strcat@plt>
  jmp    L137
L45:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: disassemble_data
arguments: data_label: D35
datatype: string
name: disassemble_data
arguments: data_label: D78
datatype: string
name: disassemble_data
arguments: data_label: D88
datatype: string
name: disassemble_data
arguments: data_label: D71
datatype: string
name: disassemble_data
arguments: data_label: D18
datatype: string
name: disassemble_data
arguments: data_label: D19
datatype: string
name: disassemble_data
arguments: data_label: D73
datatype: string
name: disassemble_data
arguments: data_label: D31
datatype: string
name: disassemble_data
arguments: data_label: D2
datatype: string

tool: D35: Character %d in this keyword is illegal. Hex Value = %X

tool: D78:  (NULL char.)

tool: D88:  (Delete char.)

tool: D71:  (Escape char.)

tool: D18:  (Carriage Return)

tool: D19:  (Form Feed char.)

tool: D73:  (Vertical Tab)

tool: D31:  (Line Feed char.)

tool: D2:  (TAB char.)

assistant: ```c
int fftrec(char *card, int *status) {
  size_t ii, maxchr;
  char msg[81];
  if (*status > 0)
    return (*status);
  maxchr = strlen(card);
  for (ii = 8; ii < maxchr; ii++) {
    if (card[ii] < 32 || card[ii] > 126) {
      snprintf(msg, 81, "Character %d in this keyword is illegal. Hex Value = %X", (int)(ii + 1), (int)card[ii]);
      if (card[ii] == 0)
        strcat(msg, " (NULL char.)");
      else if (card[ii] == 9)
        strcat(msg, " (TAB char.)");
      else if (card[ii] == 10)
        strcat(msg, " (Line Feed char.)");
      else if (card[ii] == 11)
        strcat(msg, " (Vertical Tab)");
      else if (card[ii] == 12)
        strcat(msg, " (Form Feed char.)");
      else if (card[ii] == 13)
        strcat(msg, " (Carriage Return)");
      else if (card[ii] == 27)
        strcat(msg, " (Escape char.)");
      else if (card[ii] == 127)
        strcat(msg, " (Delete char.)");
      ffpmsg(msg);
      strncpy(msg, card, 80);
      msg[80] = '\0';
      ffpmsg(msg);
      return (*status = 207);
    }
  }
  return (*status);
}
```