text: #ifndef __SYS_SEM_H__
  #define __SYS_SEM_H__
  
  /*
   * MIT License
   *
   * include/libc/sys/sem.h
   * Copyright (C) 2019 Nick Trebes
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include <sys/ipc.h>
  
  #define SEM_UNDO (1<<14)
  
  enum {
  	GETNCNT,
  	GETPID,
  	GETVAL,
  	GETALL,
  	GETZCNT,
  	SETVAL,
  	SETALL
  };
  
  int semctl(int semid, int semnum, int cmd, ...);
  int semget(key_t key, int nsems, int semflg);
  int semop(int semid, struct sembuf* sops, size_t nsops);
  
  #endif /* ! __SYS_SEM_H__ */
  