#define __STDC_WANT_LIB_EXT1__ 1
#include <stdio.h>

void main()
{
    char    filename[ L_tmpnam_s ];
    FILE    *fp;
    errno_t rc;

    rc = tmpnam_s( filename, sizeof( filename ) );
    if( rc == 0 ) {
        fp = fopen( filename, "w+b" );
        /* . */
        /* . */
        /* . */
        fclose( fp );
        remove( filename );
    }
}