getdtablesize
int getdtablesize(void);
maxfiles = getdtablesize();
maxfiles = getdtablesize();
#define _NFILE getdtablesize()
return getdtablesize();
extern int getdtablesize(void);
int getdtablesize();
tblsize = getdtablesize();
tblsize = getdtablesize();
for (i = 3; i < getdtablesize() && close(i) == 0; ++i) {