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std::strncmp(3) 	       C++ Standard Libary		 std::strncmp(3)

NAME
     std::strncmp - std::strncmp

Synopsis
	Defined in header <cstring>
	int strncmp( const char* lhs, const char* rhs, std::size_t count );

	Compares  at  most  count characters of two possibly null-terminated ar-
     rays. The
	comparison is done  lexicographically.	Characters  following  the  null
     character are
	not compared.

	The  sign of the result is the sign of the difference between the values
     of the first
	pair of characters (both interpreted as unsigned char)	that  differ  in
     the arrays
	being compared.

	The  behavior is undefined when access occurs past the end of either ar-
     ray lhs or
	rhs. The behavior is undefined when  either  lhs  or  rhs  is  the  null
     pointer.

Parameters
	lhs, rhs - pointers to the possibly null-terminated arrays to compare
	count	 - maximum number of characters to compare

Return value
	Negative value if lhs appears before rhs in lexicographical order.

	Zero if lhs and rhs compare equal, or if count is zero.

	Positive value if lhs appears after rhs in lexicographical order.

Notes
	This   function   is   not  locale-sensitive,  unlike  std::strcoll  and
     std::strxfrm.

Example
     // Run this code

      #include <cstring>
      #include <iostream>

      void demo(const char* lhs, const char* rhs, int sz)
      {
	  const int rc = std::strncmp(lhs, rhs, sz);
	  if (rc < 0)
	      std::cout << "First " << sz << " chars of ["
			<< lhs << "] precede [" << rhs << "]\n";
	  else if (rc > 0)
	      std::cout << "First " << sz << " chars of ["
			<< lhs << "] follow [" << rhs << "]\n";
	  else
	      std::cout << "First " << sz << " chars of ["
			<< lhs << "] equal [" << rhs << "]\n";
      }

      int main()
      {
	  demo("Hello, world!", "Hello, everybody!", 13);
	  demo("Hello, everybody!", "Hello, world!", 13);
	  demo("Hello, everybody!", "Hello, world!", 7);
	  demo("Hello, everybody!" + 12, "Hello, somebody!" + 11, 5);
      }

Output:
      First 13 chars of [Hello, world!] follow [Hello, everybody!]
      First 13 chars of [Hello, everybody!] precede [Hello, world!]
      First 7 chars of [Hello, everybody!] equal [Hello, world!]
      First 5 chars of [body!] equal [body!]

See also
	strcmp	compares two strings
		(function)
	wcsncmp compares a certain amount of characters from two wide strings
		(function)
	memcmp	compares two buffers
		(function)
	strcoll compares two strings in accordance to the current locale
		(function)
	C documentation for
	strncmp

http://cppreference.com 	   2024.06.10			 std::strncmp(3)
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