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

NAME
     std::tmpnam - std::tmpnam

Synopsis
	Defined in header <cstdio>
	char* tmpnam( char* filename );

	Creates  a unique filename that does not name a currently existing file,
     and stores
	it in the character string pointed to by filename. The function is capa-
     ble of
	generating up to TMP_MAX of unique filenames, but some or  all	of  them
     may already be
	in use, and thus not suitable return values.

	std::tmpnam modifies static state and is not required to be thread-safe.

Parameters
		   pointer  to	the  character array capable of holding at least
     L_tmpnam
	filename - bytes, to be used as a result buffer. If a  null  pointer  is
     passed, a
		   pointer to an internal static buffer is returned

Return value
	filename  if  filename was not a null pointer. Otherwise a pointer to an
     internal
	static buffer is returned. If no suitable filename can be  generated,  a
     null pointer
	is returned.

Notes
	Although  the  names generated by std::tmpnam are difficult to guess, it
     is possible
	that a file with that name is created by another process between the mo-
     ment
	std::tmpnam returns and the moment this program attempts to use the  re-
     turned name to
	create a file. The standard function std::tmpfile and the POSIX function
     mkstemp do
	not  have this problem (creating a unique directory using only the stan-
     dard C library
	still requires the use of tmpnam).

	POSIX systems additionally define the similarly named function	tempnam,
     which offers
	the  choice  of  a  directory  (which defaults to the optionally defined
     macro P_tmpdir).

Example
     // Run this code

      #include <cstdio>
      #include <iostream>
      #include <string>

      int main()
      {
	  std::string name1 = std::tmpnam(nullptr);
	  std::cout << "temporary file name: " << name1 << '\n';

	  char name2[L_tmpnam];
	  if (std::tmpnam(name2))
	      std::cout << "temporary file name: " << name2 << '\n';
      }

Possible output:
      temporary file name: /tmp/fileDjwifs
      temporary file name: /tmp/fileEv2bfW

See also
	tmpfile 	    creates and opens a temporary, auto-removing file
			    (function)
	temp_directory_path returns a directory suitable for temporary files
	(C++17) 	    (function)
	C documentation for
	tmpnam

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