#include <dos/dos.h>
#include <dos/dosextens.h>
#include <proto/dos.h>
#include <proto/exec.h>

#define ACTION_SET_CACHE   (15777217)

LONG main() {
  struct RDArgs *readarg;
  UBYTE template[]="DEVICE/A,LINES/A/N,READAHEAD/A/N,NOCOPYBACK/S\n";

  struct {char *name;
          ULONG *lines;
          ULONG *readahead;
          ULONG nocopyback;} arglist={NULL};

  if((DOSBase=(struct DosLibrary *)OpenLibrary("dos.library",37))!=0) {
    if((readarg=ReadArgs(template,(LONG *)&arglist,0))!=0) {
      struct MsgPort *msgport;
      struct DosList *dl;
      UBYTE *devname=arglist.name;

      while(*devname!=0) {
        if(*devname==':') {
          *devname=0;
          break;
        }
        devname++;
      }

      dl=LockDosList(LDF_DEVICES|LDF_READ);
      if((dl=FindDosEntry(dl,arglist.name,LDF_DEVICES))!=0) {
        ULONG copyback=1;
        LONG errorcode;

        if(arglist.nocopyback!=0) {
          copyback=0;
        }

        msgport=dl->dol_Task;
        UnLockDosList(LDF_DEVICES|LDF_READ);

        if((errorcode=DoPkt(msgport,ACTION_SET_CACHE,*arglist.lines,*arglist.readahead,copyback,0,0))==DOSFALSE) {
          PrintFault(IoErr(),"error while setting new cache size");
        }
        else {
          LONG bytes;

          bytes=IoErr();

          VPrintf("New cache size set.  Allocated %ld bytes of memory.\n",&bytes);
        }
      }
      else {
        VPrintf("Couldn't find device '%s:'.\n",&arglist.name);
        UnLockDosList(LDF_DEVICES|LDF_READ);
      }

      FreeArgs(readarg);
    }
    else {
      PutStr("Wrong arguments!\n");
    }
    CloseLibrary((struct Library *)DOSBase);
  }
  return(0);
}