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The C and C++ Include Header Files

cat -n /usr/include/x86_64-linux-gnu/bits/inet-fortified.h

     1	/* Checking macros for inet functions.
     2	   Copyright (C) 2025-2026 Free Software Foundation, Inc.
     3	   This file is part of the GNU C Library.
     4	
     5	   The GNU C Library is free software; you can redistribute it and/or
     6	   modify it under the terms of the GNU Lesser General Public
     7	   License as published by the Free Software Foundation; either
     8	   version 2.1 of the License, or (at your option) any later version.
     9	
    10	   The GNU C Library is distributed in the hope that it will be useful,
    11	   but WITHOUT ANY WARRANTY; without even the implied warranty of
    12	   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13	   Lesser General Public License for more details.
    14	
    15	   You should have received a copy of the GNU Lesser General Public
    16	   License along with the GNU C Library; if not, see
    17	   <https://www.gnu.org/licenses/>.  */
    18	
    19	#ifndef _BITS_INET_FORTIFIED_H
    20	#define _BITS_INET_FORTIFIED_H 1
    21	
    22	#ifndef _ARPA_INET_H
    23	# error "Never include <bits/inet-fortified.h> directly; use <arpa/inet.h> instead."
    24	#endif
    25	
    26	#include <bits/inet-fortified-decl.h>
    27	
    28	__fortify_function __attribute_overloadable__ const char *
    29	__NTH (inet_ntop (int __af,
    30		   __fortify_clang_overload_arg (const void *, __restrict, __src),
    31		   char *__restrict __dst, socklen_t __dst_size))
    32	    __fortify_clang_warning_only_if_bos_lt (__dst_size, __dst,
    33						    "inet_ntop called with bigger length "
    34						    "than size of destination buffer")
    35	{
    36	  return __glibc_fortify (inet_ntop, __dst_size, sizeof (char),
    37				  __glibc_objsize (__dst),
    38				  __af, __src, __dst, __dst_size);
    39	};
    40	
    41	__fortify_function __attribute_overloadable__ int
    42	__NTH (inet_pton (int __af,
    43		   const char *__restrict __src,
    44		   __fortify_clang_overload_arg (void *, __restrict, __dst)))
    45	    __fortify_clang_warning_only_if_bos0_lt
    46		(4, __dst, "inet_pton called with destination buffer size less than 4")
    47	{
    48	#if !__fortify_use_clang
    49	  size_t __sz = 0;
    50	  if (__af == AF_INET)
    51	    __sz = sizeof (struct in_addr);
    52	  else if (__af == AF_INET6)
    53	    __sz = sizeof (struct in6_addr);
    54	  else
    55	    return __inet_pton_alias (__af, __src, __dst);
    56	#endif
    57	
    58	  return __glibc_fortify (inet_pton, __sz, sizeof (char),
    59				  __glibc_objsize (__dst),
    60				  __af, __src, __dst);
    61	};
    62	
    63	#endif /* bits/inet-fortified.h.  */