minix/lib/libc/sys/sbrk.c


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#include <sys/cdefs.h>
#include "namespace.h"
#include <lib.h>

#include <unistd.h>

#ifdef __weak_alias
__weak_alias(sbrk, _sbrk)
#endif

extern char *_brksize;

void *sbrk(incr)
intptr_t incr;
{
  char *newsize, *oldsize;

  oldsize = _brksize;
  newsize = _brksize + incr;
  if ((incr > 0 && newsize < oldsize) || (incr < 0 && newsize > oldsize))
	return( (char *) -1);
  if (brk(newsize) == 0)
	return(oldsize);
  else
	return( (char *) -1);
}