1  /* Example of a Variadic Function
       2     Copyright (C) 1991-2023 Free Software Foundation, Inc.
       3  
       4     This program is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU General Public License
       6     as published by the Free Software Foundation; either version 2
       7     of the License, or (at your option) any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU General Public License for more details.
      13  
      14     You should have received a copy of the GNU General Public License
      15     along with this program; if not, see <https://www.gnu.org/licenses/>.
      16  */
      17  
      18  #include <stdarg.h>
      19  #include <stdio.h>
      20  
      21  int
      22  add_em_up (int count,...)
      23  {
      24    va_list ap;
      25    int i, sum;
      26  
      27    va_start (ap, count);		/* Initialize the argument list. */
      28  
      29    sum = 0;
      30    for (i = 0; i < count; i++)
      31      sum += va_arg (ap, int);	/* Get the next argument value. */
      32  
      33    va_end (ap);			/* Clean up. */
      34    return sum;
      35  }
      36  
      37  int
      38  main (void)
      39  {
      40    /* This call prints 16. */
      41    printf ("%d\n", add_em_up (3, 5, 5, 6));
      42  
      43    /* This call prints 55. */
      44    printf ("%d\n", add_em_up (10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
      45  
      46    return 0;
      47  }