user: 请从给定的汇编指令推导出C源代码：

```asm
<main>:
  endbr64
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x8(%rsp)
  xor    %eax,%eax
  call   <getpid@plt>
  mov    %eax,%esi
  lea    D23(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  call   <fork@plt>
  mov    %eax,%ebx
  mov    $0x0,%eax
  call   <getpid@plt>
  cmp    $0xffffffff,%ebx
  je     L46
  mov    %eax,%ebp
  test   %ebx,%ebx
  jle    L19
  mov    $0x0,%eax
  call   <getppid@plt>
  mov    %eax,%ecx
  mov    %ebx,%edx
  mov    %ebp,%esi
  lea    D27(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    0x4(%rsp),%rsi
  mov    $0x0,%edx
  mov    %ebx,%edi
  call   <waitpid@plt>
  mov    %eax,%ebx
  mov    0x4(%rsp),%edi
  call   <WIFEXITED@plt>
  mov    %eax,%edx
  mov    %ebx,%esi
  lea    D42(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  mov    $0x0,%eax
L18:
  mov    0x8(%rsp),%rdx
  sub    %fs:0x28,%rdx
  jne    L55
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  ret
L46:
  lea    D77(%rip),%rdi
  call   <puts@plt>
  mov    $0x1,%eax
  jmp    L18
L19:
  mov    $0x0,%eax
  call   <getppid@plt>
  mov    %eax,%edx
  mov    %ebp,%esi
  lea    D21(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    D56(%rip),%rbx
  mov    %rbx,%rdi
  call   <system@plt>
  mov    %eax,%esi
  lea    D13(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  mov    $0x0,%r8d
  mov    $0x0,%ecx
  mov    $0x0,%edx
  mov    %rbx,%rsi
  lea    D67(%rip),%rdi
  call   <execle@plt>
  mov    %eax,%edx
  mov    $0x0,%eax
  cmp    $0xffffffff,%edx
  jne    L18
  lea    D16(%rip),%rdi
  call   <puts@plt>
  mov    $0x0,%eax
  jmp    L18
L55:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: retrieve_data
arguments: tag: D23
type: string
name: retrieve_data
arguments: tag: D27
type: string
name: retrieve_data
arguments: tag: D42
type: string
name: retrieve_data
arguments: tag: D77
type: string
name: retrieve_data
arguments: tag: D21
type: string
name: retrieve_data
arguments: tag: D56
type: string
name: retrieve_data
arguments: tag: D13
type: string
name: retrieve_data
arguments: tag: D67
type: string
name: retrieve_data
arguments: tag: D16
type: string

tool: D23: pid:%d


tool: D27: parent %d's child %d, parent %d.


tool: D42: wait return %d, WIFEXITED=%d.


tool: D77: failed to fork.

tool: D21: child %d's parent %d.


tool: D56: date

tool: D13: system() return %d.


tool: D67: /bin/date

tool: D16: failed to exec. 

assistant: ```c
int main() {
  pid_t pid = getpid();
  printf("pid:%d\n", pid);
  pid_t fork_pid = fork();
  pid = getpid();
  if (fork_pid == -1) {
    puts("failed to fork.");
    return 1;
  } else if (fork_pid > 0) {
    printf("parent %d's child %d, parent %d.\n", pid, fork_pid, getppid());
    int status;
    pid_t wait_pid;
    wait_pid = waitpid(fork_pid, &status, 0);
    printf("wait return %d, WIFEXITED=%d.\n", wait_pid, WIFEXITED(status));
  } else {
    printf("child %d's parent %d.\n", pid, getppid());
    int system_ret = system("date");
    printf("system() return %d.\n", system_ret);
    int exec_ret = execle("/bin/date", "date", 0, 0, NULL);
    if (exec_ret == -1) {
      puts("failed to exec. ");
    }
  }
  return 0;
}
```