yes.c

//  Copyright (C) 2021 Benjamin Stürz
//  
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//  
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//  
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.

#define PROG_NAME "yes"

#include <stdio.h>

int main(int argc, char** argv) {
   if (argc == 1) {
      while (1) {
         puts("y");
      }
   } else {
      while (1) {
         printf("%s", argv[1]);
         for (int i = 2; i < argc; ++i)
            printf(" %s", argv[i]);
         putchar(' ');
      }
   }
   return 0;
}