text: #include	<stdio.h>
  #include	<unistd.h>
  #include	<limits.h>
  #include	<time.h>
  #include	<errno.h>
  #include	<sys/limits.h>
  
  long
  sysconf(int name)
  {
  	switch(name)
  	{
  	case _SC_ARG_MAX:
  		return ARG_MAX;
  	case _SC_CHILD_MAX:
  		return CHILD_MAX;
  	case _SC_CLK_TCK:
  		return CLOCKS_PER_SEC;
  	case _SC_NGROUPS_MAX:
  		return NGROUPS_MAX;
  	case _SC_OPEN_MAX:
  		return OPEN_MAX;
  	case _SC_JOB_CONTROL:
  #ifdef	_POSIX_JOB_CONTROL
  		return _POSIX_JOB_CONTROL;
  #else
  		return -1;
  #endif
  	case _SC_SAVED_IDS:
  #ifdef	_POSIX_SAVED_IDS
  		return _POSIX_SAVED_IDS;
  #else
  		return -1;
  #endif
  	case _SC_VERSION:
  		return _POSIX_VERSION;
  	case _SC_LOGIN_NAME_MAX:
  		return L_cuserid;
  	}
  	errno = EINVAL;
  	return -1;
  }
  