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

```asm
<lookup>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x18,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  mov    $0x2e,%esi
  call   <strrchr@plt>
  mov    %rax,%r12
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %eax,%r15d
  lea    0x1(%rax),%eax
  cltq
  add    $0xf,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffffff0,%rcx
  and    $0xfffffffffffff000,%rax
  mov    %rsp,%rdx
  sub    %rax,%rdx
L91:
  cmp    %rdx,%rsp
  je     L89
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L91
L89:
  mov    %rcx,%rax
  and    $0xfff,%eax
  sub    %rax,%rsp
  test   %rax,%rax
  je     L26
  orq    $0x0,-0x8(%rsp,%rax,1)
L26:
  mov    %rsp,%r13
  test   %r15d,%r15d
  jle    L103
  mov    %r15d,%r14d
  mov    $0x0,%ebx
L72:
  movsbl (%r12,%rbx,1),%edi
  call   <tolower@plt>
  mov    %al,0x0(%r13,%rbx,1)
  add    $0x1,%rbx
  cmp    %r14,%rbx
  jne    L72
L103:
  movslq %r15d,%r15
  movb   $0x0,0x0(%r13,%r15,1)
  lea    D83(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%rdx
  lea    D65(%rip),%rax
  test   %rdx,%rdx
  jne    L2
L41:
  mov    -0x38(%rbp),%rdx
  sub    %fs:0x28,%rdx
  jne    L8
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
L2:
  lea    D1(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%rdx
  lea    D113(%rip),%rax
  test   %rdx,%rdx
  je     L41
  lea    D56(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%rdx
  lea    D107(%rip),%rax
  test   %rdx,%rdx
  je     L41
  lea    D11(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%rdx
  lea    D146(%rip),%rax
  test   %rdx,%rdx
  je     L41
  lea    D101(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%rdx
  lea    D13(%rip),%rax
  test   %rdx,%rdx
  je     L41
  lea    D5(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%rdx
  lea    D7(%rip),%rax
  test   %rdx,%rdx
  je     L41
  lea    D143(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%rdx
  lea    D93(%rip),%rax
  test   %rdx,%rdx
  je     L41
  lea    D21(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  test   %rax,%rax
  lea    D156(%rip),%rax
  mov    $0x0,%edx
  cmovne %rdx,%rax
  jmp    L41
L8:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: retrieve_data
arguments: data_tag: D83
type: string
name: retrieve_data
arguments: data_tag: D65
type: string
name: retrieve_data
arguments: data_tag: D1
type: string
name: retrieve_data
arguments: data_tag: D113
type: string
name: retrieve_data
arguments: data_tag: D56
type: string
name: retrieve_data
arguments: data_tag: D107
type: string
name: retrieve_data
arguments: data_tag: D11
type: string
name: retrieve_data
arguments: data_tag: D146
type: string
name: retrieve_data
arguments: data_tag: D101
type: string
name: retrieve_data
arguments: data_tag: D13
type: string
name: retrieve_data
arguments: data_tag: D5
type: string
name: retrieve_data
arguments: data_tag: D7
type: string
name: retrieve_data
arguments: data_tag: D143
type: string
name: retrieve_data
arguments: data_tag: D93
type: string
name: retrieve_data
arguments: data_tag: D21
type: string
name: retrieve_data
arguments: data_tag: D156
type: string

tool: D83: .css

tool: D65: text/css

tool: D1: .html

tool: D113: text/html

tool: D56: .gif

tool: D107: image/gif

tool: D11: .ico

tool: D146: image/x-icon

tool: D101: .jpg

tool: D13: image/jpeg

tool: D5: .js

tool: D7: text/javascript

tool: D143: .php

tool: D93: text/x-php

tool: D21: .png

tool: D156: image/png

assistant: ```c
const char *lookup(const char *path) {
  char *suffixPtr = strrchr(path, '.');
  int suffixLength = strlen(suffixPtr);
  char suffix[suffixLength + 1];
  for (int i = 0; i < suffixLength; i++) {
    suffix[i] = tolower(suffixPtr[i]);
  }
  suffix[suffixLength] = '\0';
  if (strcmp(suffix, ".css") == 0)
    return "text/css";
  else if (strcmp(suffix, ".html") == 0)
    return "text/html";
  else if (strcmp(suffix, ".gif") == 0)
    return "image/gif";
  else if (strcmp(suffix, ".ico") == 0)
    return "image/x-icon";
  else if (strcmp(suffix, ".jpg") == 0)
    return "image/jpeg";
  else if (strcmp(suffix, ".js") == 0)
    return "text/javascript";
  else if (strcmp(suffix, ".php") == 0)
    return "text/x-php";
  else if (strcmp(suffix, ".png") == 0)
    return "image/png";
  else
    return NULL;
}
```