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

```asm
<DWBhome>:
  endbr64
  push   %r15
  lea    D35(%rip),%rsi
  lea    D3(%rip),%rdi
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0xe8,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0xd8(%rsp)
  xor    %eax,%eax
  call   <fopen@plt>
  test   %rax,%rax
  je     L147
  lea    D31(%rip),%r14
  mov    %rax,%rbp
  lea    0x10(%rsp),%rbx
  xor    %r12d,%r12d
  mov    %r14,%rdi
  call   <strlen@plt>
  mov    %eax,%r13d
  cltq
  mov    %rax,(%rsp)
  nopw   0x0(%rax,%rax,1)
L152:
  mov    %rbp,%rdx
  mov    $0xc8,%esi
  mov    %rbx,%rdi
  call   <fgets@plt>
  test   %rax,%rax
  je     L196
  mov    %rbx,%r15
  jmp    L7
  xchg   %ax,%ax
L5:
  add    $0x1,%r15
L7:
  movsbl (%r15),%edi
  call   <isspace@plt>
  test   %rax,%rax
  jne    L5
  mov    %r13d,%edx
  mov    %r14,%rsi
  mov    %r15,%rdi
  call   <strncmp@plt>
  test   %rax,%rax
  jne    L152
  mov    (%rsp),%rax
  cmpb   $0x3d,(%r15,%rax,1)
  jne    L152
  lea    0x1(%r15,%rax,1),%rax
  mov    %rax,0x8(%rsp)
  mov    %rax,%r15
  jmp    L67
  nop
L42:
  cmpb   $0x3b,(%r15)
  je     L40
  add    $0x1,%r15
L67:
  movsbl (%r15),%edi
  call   <isspace@plt>
  test   %rax,%rax
  je     L42
L40:
  movb   $0x0,(%r15)
  test   %r12,%r12
  je     L164
  mov    %r12,%rdi
  call   <free@plt>
L164:
  mov    0x8(%rsp),%r15
  mov    %r15,%rdi
  call   <strlen@plt>
  lea    0x1(%rax),%edi
  call   <malloc@plt>
  mov    %rax,%r12
  test   %rax,%rax
  je     L152
  mov    %r15,%rsi
  mov    %rax,%rdi
  call   <strcpy@plt>
  jmp    L152
  nopw   0x0(%rax,%rax,1)
L196:
  mov    %rbp,%rdi
  call   <fclose@plt>
  test   %r12,%r12
  jne    L14
  mov    %r14,%rdi
  call   <getenv@plt>
  mov    %rax,%r12
  test   %rax,%rax
  jne    L14
  nopl   (%rax)
L47:
  mov    0xd8(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L63
  add    $0xe8,%rsp
  mov    %r12,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax,%rax,1)
L167:
  cmpb   $0x2f,0x1(%r12)
  jne    L47
  add    $0x1,%r12
L14:
  cmpb   $0x2f,(%r12)
  je     L167
  jmp    L47
L147:
  lea    D31(%rip),%r14
  mov    %r14,%rdi
  call   <getenv@plt>
  mov    %rax,%r12
  test   %rax,%rax
  jne    L14
  jmp    L47
L63:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: read_data
arguments: tag: D35
type_infered: string
name: read_data
arguments: tag: D3
type_infered: string
name: read_data
arguments: tag: D31
type_infered: string

tool: D35: r

tool: D3: /dev/null

tool: D31: DWBHOME

assistant: ```c
char *DWBhome(void) {
  FILE *fp;
  char *ptr;
  char *path;
  int len;
  char buf[200];
  char *home = NULL;
  if ((fp = fopen("/dev/null", "r")) != NULL) {
    len = strlen("DWBHOME");
    while (fgets(buf, sizeof(buf), fp) != NULL) {
      for (ptr = buf; isspace(*ptr); ptr++)
        ;
      if (strncmp(ptr, "DWBHOME", len) == 0 && *(ptr + len) == '=') {
        path = ptr + len + 1;
        for (ptr = path; !isspace(*ptr) && *ptr != ';'; ptr++)
          ;
        *ptr = '\0';
        if (home != NULL)
          free(home);
        if ((home = malloc(strlen(path) + 1)) != NULL)
          strcpy(home, path);
      }
    }
    fclose(fp);
  }
  if (home == NULL) {
    if ((home = getenv("DWBHOME")) == NULL) {
      if ((home = "") == NULL || *home == '\0' || *home == ' ')
        home = NULL;
    }
  }
  while (home && *home == '/' && *(home + 1) == '/')
    home++;
  return (home);
}
```