ssiLink.h File Reference

#include <Singular/links/silink.h>

Go to the source code of this file.

Functions
BOOLEAN	ssiOpen (si_link l, short flag, leftv u)
BOOLEAN	ssiWrite (si_link l, leftv v)
leftv	ssiRead1 (si_link l)
leftv	ssiRead2 (si_link l, leftv key)
BOOLEAN	ssiClose (si_link l)
const char *	slStatusSsi (si_link l, const char *request)
si_link_extension	slInitSsiExtension (si_link_extension s)
void	sig_chld_hdl (int sig)
	additional default signal handler More...

Function Documentation

void sig_chld_hdl

(

int

)

additional default signal handler

some newer Linux version cannot have SIG_IGN for SIGCHLD, so use this nice routine here: SuSe 9.x reports -1 always Redhat 9.x/FC x reports sometimes -1 see also: hpux_system also needed by getrusage (timer etc.)

Parameters

[in]

sig

Definition at line 1890 of file ssiLink.cc.

{
  pid_t kidpid;
  int status;

  loop
  {
    kidpid = si_waitpid(-1, &status, WNOHANG);
    if (kidpid==-1)
    {
      /* continue on interruption (EINTR): */
      if (errno == EINTR) continue;
      /* break on anything else (EINVAL or ECHILD according to manpage): */
      break;
    }
    else if (kidpid==0) break; /* no more children to process, so break */

    //printf("Child %ld terminated\n", kidpid);
    link_list hh=ssiToBeClosed;
    while((hh!=NULL)&&(ssiToBeClosed_inactive))
    {
      if((hh->l!=NULL) && (hh->l->m->Open==ssiOpen))
      {
        ssiInfo *d = (ssiInfo *)hh->l->data;
        if(d->pid==kidpid)
        {
          if(ssiToBeClosed_inactive)
          {
            ssiToBeClosed_inactive=FALSE;
            slClose(hh->l);
            ssiToBeClosed_inactive=TRUE;
            break;
          }
          else break;
        }
        else hh=(link_list)hh->next;
      }
      else hh=(link_list)hh->next;
    }
  }
}

si_link_extension slInitSsiExtension

(

si_link_extension

s

)

Definition at line 1504 of file ssiLink.cc.

{
  s->Open=ssiOpen;
  s->Close=ssiClose;
  s->Kill=ssiClose;
  s->Read=ssiRead1;
  s->Read2=(slRead2Proc)NULL;
  s->Write=ssiWrite;
  s->Dump=ssiDump;
  s->GetDump=ssiGetDump;

  s->Status=slStatusSsi;
  s->SetRing=ssiSetRing;
  s->type="ssi";
  return s;
}

const char* slStatusSsi	(	si_link	l,
		const char *	request
	)

Definition at line 1521 of file ssiLink.cc.

{
  ssiInfo *d=(ssiInfo*)l->data;
  if (d==NULL) return "not open";
  if (((strcmp(l->mode,"fork")==0)
  ||(strcmp(l->mode,"tcp")==0)
  ||(strcmp(l->mode,"connect")==0))
  && (strcmp(request, "read") == 0))
  {
    fd_set  mask;
    struct timeval wt;
    if (s_isready(d->f_read)) return "ready";
    loop
    {
      /* Don't block. Return socket status immediately. */
      wt.tv_sec  = 0;
      wt.tv_usec = 0;

      FD_ZERO(&mask);
      FD_SET(d->fd_read, &mask);
      //Print("test fd %d\n",d->fd_read);
    /* check with select: chars waiting: no -> not ready */
      switch (si_select(d->fd_read+1, &mask, NULL, NULL, &wt))
      {
        case 0: /* not ready */ return "not ready";
        case -1: /*error*/      return "error";
        case 1: /*ready ? */    break;
      }
    /* yes: read 1 char*/
    /* if \n, check again with select else ungetc(c), ready*/
      int c=s_getc(d->f_read);
      //Print("try c=%d\n",c);
      if (c== -1) return "eof"; /* eof or error */
      else if (isdigit(c))
      { s_ungetc(c,d->f_read); return "ready"; }
      else if (c>' ')
      {
        Werror("unknown char in ssiLink(%d)",c);
        return "error";
      }
      /* else: next char */
    }
  }
  else if (strcmp(request, "read") == 0)
  {
    if (SI_LINK_R_OPEN_P(l) && (!s_iseof(d->f_read)) && (s_isready(d->f_read))) return "ready";
    else return "not ready";
  }
  else if (strcmp(request, "write") == 0)
  {
    if (SI_LINK_W_OPEN_P(l)) return "ready";
    else return "not ready";
  }
  else return "unknown status request";
}

BOOLEAN ssiClose

(

si_link

l

)

Definition at line 1128 of file ssiLink.cc.

{
  if (l!=NULL)
  {
    SI_LINK_SET_CLOSE_P(l);
    ssiInfo *d = (ssiInfo *)l->data;
    if (d!=NULL)
    {
      if ((d->send_quit_at_exit)
      && (d->quit_sent==0))
      {
        fputs("99\n",d->f_write);
        fflush(d->f_write);
      }
      if (d->r!=NULL) rKill(d->r);
      if ((d->pid!=0)
      && (si_waitpid(d->pid,NULL,WNOHANG)==0))
      {
        struct timespec t;
        t.tv_sec=0;
        t.tv_nsec=100000000; // <=100 ms
        struct timespec rem;
        int r;
        do
        {
          r = nanosleep(&t, &rem);
          t = rem;
        } while ((r < 0) && (errno == EINTR)
            && (si_waitpid(d->pid,NULL,WNOHANG) == 0));
        if ((r == 0) && (si_waitpid(d->pid,NULL,WNOHANG) == 0))
        {
          kill(d->pid,15);
          t.tv_sec=5; // <=5s
          t.tv_nsec=0;
          do
          {
            r = nanosleep(&t, &rem);
            t = rem;
          } while ((r < 0) && (errno == EINTR)
              && (si_waitpid(d->pid,NULL,WNOHANG) == 0));
          if ((r == 0) && (si_waitpid(d->pid,NULL,WNOHANG) == 0))
          {
            kill(d->pid,9); // just to be sure
            si_waitpid(d->pid,NULL,0);
          }
        }
      }
      if (d->f_read!=NULL) s_close(d->f_read);
      if (d->f_read!=NULL) s_free(d->f_read);
      if (d->f_write!=NULL) fclose(d->f_write);
      if ((strcmp(l->mode,"tcp")==0)
      || (strcmp(l->mode,"fork")==0))
      {
        link_list hh=ssiToBeClosed;
        if (hh!=NULL)
        {
          if (hh->l==l)
          {
             ssiToBeClosed=(link_list)hh->next;
             omFreeSize(hh,sizeof(link_struct));
          }
          else while(hh->next!=NULL)
          {
            link_list hhh=(link_list)hh->next;
            if (hhh->l==l)
            {
              hh->next=hhh->next;
              omFreeSize(hhh,sizeof(link_struct));
              break;
            }
            else
              hh=(link_list)hh->next;
          }
        }
      }
      omFreeSize((ADDRESS)d,(sizeof *d));
    }
    l->data=NULL;
  }
  return FALSE;
}

BOOLEAN ssiOpen	(	si_link	l,
		short	flag,
		leftv	u
	)

Definition at line 747 of file ssiLink.cc.

{
  if (l!=NULL)
  {
    const char *mode;
    ssiInfo *d=(ssiInfo*)omAlloc0(sizeof(ssiInfo));
    if (flag & SI_LINK_OPEN)
    {
      if (l->mode[0] != '\0' && (strcmp(l->mode, "r") == 0))
        flag = SI_LINK_READ;
      else flag = SI_LINK_WRITE;
    }

    if (flag == SI_LINK_READ) mode = "r";
    else if (strcmp(l->mode, "w") == 0) mode = "w";
    else if (strcmp(l->mode, "fork") == 0) mode = "fork";
    else if (strcmp(l->mode, "tcp") == 0) mode = "tcp";
    else if (strcmp(l->mode, "connect") == 0) mode = "connect";
    else mode = "a";


    SI_LINK_SET_OPEN_P(l, flag);
    l->data=d;
    omFree(l->mode);
    l->mode = omStrDup(mode);

    if (l->name[0] == '\0')
    {
      if (strcmp(mode,"fork")==0)
      {
        link_list n=(link_list)omAlloc(sizeof(link_struct));
        n->u=u;
        n->l=l;
        n->next=(void *)ssiToBeClosed;
        ssiToBeClosed=n;

        int pc[2];
        int cp[2];
        pipe(pc);
        pipe(cp);
        pid_t pid = fork();
        if (pid == -1 && errno == EAGAIN)   // RLIMIT_NPROC too low?
        {
          raise_rlimit_nproc();
          pid = fork();
        }
        if (pid == -1)
        {
          WerrorS("could not fork");
        }
        if (pid==0) /*fork: child*/
        {
          /* block SIGINT */
          sigset_t sigint;
          sigemptyset(&sigint);
          sigaddset(&sigint, SIGINT);
          sigprocmask(SIG_BLOCK, &sigint, NULL);

          link_list hh=(link_list)ssiToBeClosed->next;
          /* we know: l is the first entry in ssiToBeClosed-list */
          while(hh!=NULL)
          {
            SI_LINK_SET_CLOSE_P(hh->l);
            ssiInfo *dd=(ssiInfo*)hh->l->data;
            s_close(dd->f_read);
            s_free(dd->f_read);
            fclose(dd->f_write);
            if (dd->r!=NULL) rKill(dd->r);
            omFreeSize((ADDRESS)dd,(sizeof *dd));
            hh->l->data=NULL;
            link_list nn=(link_list)hh->next;
            omFree(hh);
            hh=nn;
          }
          ssiToBeClosed->next=NULL;
#ifdef HAVE_SIMPLEIPC
          memset(sem_acquired, 0, SIPC_MAX_SEMAPHORES*sizeof(sem_acquired[0]));
#endif   // HAVE_SIMPLEIPC
          si_close(pc[1]); si_close(cp[0]);
          d->f_write=fdopen(cp[1],"w");
          d->f_read=s_open(pc[0]);
          d->fd_read=pc[0];
          d->fd_write=cp[1];
          //d->r=currRing;
          //if (d->r!=NULL) d->r->ref++;
          l->data=d;
          omFree(l->mode);
          l->mode = omStrDup(mode);
          singular_in_batchmode=TRUE;
          SI_LINK_SET_RW_OPEN_P(l);
          //myynest=0;
          fe_fgets_stdin=fe_fgets_dummy;
          if ((u!=NULL)&&(u->rtyp==IDHDL))
          {
            idhdl h=(idhdl)u->data;
            h->lev=0;
          }
          loop
          {
            leftv h=ssiRead1(l); /*contains an exit.... */
            if (feErrors != NULL && *feErrors != '\0')
            {
              // handle errors:
              PrintS(feErrors); /* currently quite simple */
              *feErrors = '\0';
            }
            ssiWrite(l,h);
            h->CleanUp();
            omFreeBin(h, sleftv_bin);
          }
          /* never reached*/
        }
        else if (pid>0) /*fork: parent*/
        {
          d->pid=pid;
          si_close(pc[0]); si_close(cp[1]);
          d->f_write=fdopen(pc[1],"w");
          d->f_read=s_open(cp[0]);
          d->fd_read=cp[0];
          d->fd_write=pc[1];
          SI_LINK_SET_RW_OPEN_P(l);
          d->send_quit_at_exit=1;
          //d->r=currRing;
          //if (d->r!=NULL) d->r->ref++;
        }
        else
        {
          Werror("fork failed (%d)",errno);
          l->data=NULL;
          omFree(d);
          return TRUE;
        }
      }
      // ---------------------------------------------------------------------
      else if (strcmp(mode,"tcp")==0)
      {
        int sockfd, newsockfd, portno, clilen;
        struct sockaddr_in serv_addr, cli_addr;
        sockfd = socket(AF_INET, SOCK_STREAM, 0);
        if(sockfd < 0)
        {
          WerrorS("ERROR opening socket");
          l->data=NULL;
          omFree(d);
          return TRUE;
        }
        memset((char *) &serv_addr,0, sizeof(serv_addr));
        portno = 1025;
        serv_addr.sin_family = AF_INET;
        serv_addr.sin_addr.s_addr = INADDR_ANY;
        do
        {
          portno++;
          serv_addr.sin_port = htons(portno);
          if(portno > 50000)
          {
            WerrorS("ERROR on binding (no free port available?)");
            l->data=NULL;
            omFree(d);
            return TRUE;
          }
        }
        while(bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0);
        Print("waiting on port %d\n", portno);mflush();
        listen(sockfd,1);
        newsockfd = si_accept(sockfd, (struct sockaddr *) &cli_addr, (socklen_t *)&clilen);
        if(newsockfd < 0)
        {
          WerrorS("ERROR on accept");
          l->data=NULL;
          omFree(d);
          return TRUE;
        }
        PrintS("client accepted\n");
        d->fd_read = newsockfd;
        d->fd_write = newsockfd;
        d->f_read = s_open(newsockfd);
        d->f_write = fdopen(newsockfd, "w");
        SI_LINK_SET_RW_OPEN_P(l);
        si_close(sockfd);
      }
      // no ssi-Link on stdin or stdout
      else
      {
        Werror("invalid mode >>%s<< for ssi",mode);
        l->data=NULL;
        omFree(d);
        return TRUE;
      }
    }
    // =========================================================================
    else /*l->name=NULL*/
    {
      // tcp mode
      if(strcmp(mode,"tcp")==0)
      {
        int sockfd, newsockfd, portno, clilen;
        struct sockaddr_in serv_addr, cli_addr;
        sockfd = socket(AF_INET, SOCK_STREAM, 0);
        if(sockfd < 0)
        {
          WerrorS("ERROR opening socket");
          l->data=NULL;
          omFree(d);
          return TRUE;
        }
        memset((char *) &serv_addr,0, sizeof(serv_addr));
        portno = 1025;
        serv_addr.sin_family = AF_INET;
        serv_addr.sin_addr.s_addr = INADDR_ANY;
        do
        {
          portno++;
          serv_addr.sin_port = htons(portno);
          if(portno > 50000)
          {
            WerrorS("ERROR on binding (no free port available?)");
            l->data=NULL;
            return TRUE;
          }
        }
        while(bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0);
        //Print("waiting on port %d\n", portno);mflush();
        listen(sockfd,1);
        char* cli_host = (char*)omAlloc(256);
        char* path = (char*)omAlloc(1024);
        int r = si_sscanf(l->name,"%255[^:]:%s",cli_host,path);
        if(r == 0)
        {
          WerrorS("ERROR: no host specified");
          l->data=NULL;
          omFree(d);
          omFree(path);
          omFree(cli_host);
          return TRUE;
        }
        else if(r == 1)
        {
          WarnS("program not specified, using /usr/local/bin/Singular");
          strcpy(path,"/usr/local/bin/Singular");
        }
        char* ssh_command = (char*)omAlloc(256);
        char* ser_host = (char*)omAlloc(64);
        gethostname(ser_host,64);
        sprintf(ssh_command,"ssh %s %s -q --batch --link=ssi --MPhost=%s --MPport=%d &",cli_host,path,ser_host,portno);
        //Print("client on %s started:%s\n",cli_host,path);
        omFree(path);
        omFree(cli_host);
        if (TEST_OPT_PROT) { Print("running >>%s<<\n",ssh_command); }
        system(ssh_command);
        omFree(ssh_command);
        omFree(ser_host);
        clilen = sizeof(cli_addr);
        newsockfd = si_accept(sockfd, (struct sockaddr *) &cli_addr, (socklen_t *)&clilen);
        if(newsockfd < 0)
        {
          WerrorS("ERROR on accept");
          l->data=NULL;
          omFree(d);
          return TRUE;
        }
        //PrintS("client accepted\n");
        d->fd_read = newsockfd;
        d->fd_write = newsockfd;
        d->f_read = s_open(newsockfd);
        d->f_write = fdopen(newsockfd, "w");
        si_close(sockfd);
        SI_LINK_SET_RW_OPEN_P(l);
        d->send_quit_at_exit=1;
        link_list newlink=(link_list)omAlloc(sizeof(link_struct));
        newlink->u=u;
        newlink->l=l;
        newlink->next=(void *)ssiToBeClosed;
        ssiToBeClosed=newlink;
        fprintf(d->f_write,"98 %d %d %u %u\n",SSI_VERSION,MAX_TOK,si_opt_1,si_opt_2);
      }
      // ----------------------------------------------------------------------
      else if(strcmp(mode,"connect")==0)
      {
        char* host = (char*)omAlloc(256);
        int sockfd, portno;
        struct sockaddr_in serv_addr;
        struct hostent *server;

        si_sscanf(l->name,"%255[^:]:%d",host,&portno);
        //Print("connect to host %s, port %d\n",host,portno);mflush();
        if (portno!=0)
        {
          sockfd = socket(AF_INET, SOCK_STREAM, 0);
          if (sockfd < 0) { WerrorS("ERROR opening socket"); return TRUE; }
          server = gethostbyname(host);
          if (server == NULL) {  WerrorS("ERROR, no such host");  return TRUE; }
          memset((char *) &serv_addr, 0, sizeof(serv_addr));
          serv_addr.sin_family = AF_INET;
          memcpy((char *)&serv_addr.sin_addr.s_addr,
                (char *)server->h_addr,
                server->h_length);
          serv_addr.sin_port = htons(portno);
          if (si_connect(sockfd,(sockaddr*)&serv_addr,sizeof(serv_addr)) < 0)
          { Werror("ERROR connecting(errno=%d)",errno); return TRUE; }
          //PrintS("connected\n");mflush();
          d->f_read=s_open(sockfd);
          d->fd_read=sockfd;
          d->f_write=fdopen(sockfd,"w");
          d->fd_write=sockfd;
          SI_LINK_SET_RW_OPEN_P(l);
          omFree(host);
        }
        else
        {
          l->data=NULL;
          omFree(d);
          return TRUE;
        }
      }
      // ======================================================================
      else
      {
        // normal link to a file
        FILE *outfile;
        char *filename=l->name;

        if(filename[0]=='>')
        {
          if (filename[1]=='>')
          {
            filename+=2;
            mode = "a";
          }
          else
          {
            filename++;
            mode="w";
          }
        }
        outfile=myfopen(filename,mode);
        if (outfile!=NULL)
        {
          if (strcmp(l->mode,"r")==0)
          {
            fclose(outfile);
            d->f_read=s_open_by_name(filename);
          }
          else
          {
            d->f_write = outfile;
            fprintf(d->f_write,"98 %d %d %u %u\n",SSI_VERSION,MAX_TOK,si_opt_1,si_opt_2);
          }
        }
        else
        {
          omFree(d);
          l->data=NULL;
          return TRUE;
        }
      }
    }
  }

  return FALSE;
}

leftv ssiRead1

(

si_link

l

)

Definition at line 1211 of file ssiLink.cc.

{
  ssiInfo *d = (ssiInfo *)l->data;
  leftv res=(leftv)omAlloc0(sizeof(sleftv));
  int t=0;
  t=s_readint(d->f_read);
  //Print("got type %d\n",t);
  switch(t)
  {
    case 1:res->rtyp=INT_CMD;
           res->data=(char *)(long)ssiReadInt(d->f_read);
           break;
    case 2:res->rtyp=STRING_CMD;
           res->data=(char *)ssiReadString(d);
           break;
    case 3:res->rtyp=NUMBER_CMD;
           res->data=(char *)ssiReadNumber(d);
           break;
    case 4:res->rtyp=BIGINT_CMD;
           res->data=(char *)ssiReadBigInt(d);
           break;
    case 15:
    case 5:{
             d->r=ssiReadRing(d);
             res->data=(char*)d->r;
             if (d->r->qideal==NULL)
               res->rtyp=RING_CMD;
             else
               res->rtyp=QRING_CMD;
             // we are in the top-level, so set the basering to d->r:
             if (d->r!=NULL)
             {
               d->r->ref++;
               ssiSetCurrRing(d->r);
             }
             if (t==15) return ssiRead1(l);
           }
           break;
    case 6:res->rtyp=POLY_CMD;
           if (d->r==NULL) goto no_ring;
           res->data=(char*)ssiReadPoly(d);
           break;
    case 7:res->rtyp=IDEAL_CMD;
           if (d->r==NULL) goto no_ring;
           res->data=(char*)ssiReadIdeal(d);
           break;
    case 8:res->rtyp=MATRIX_CMD;
           if (d->r==NULL) goto no_ring;
           res->data=(char*)ssiReadMatrix(d);
           break;
    case 9:res->rtyp=VECTOR_CMD;
           if (d->r==NULL) goto no_ring;
           res->data=(char*)ssiReadPoly(d);
           break;
    case 10:res->rtyp=MODUL_CMD;
           if (d->r==NULL) goto no_ring;
           res->data=(char*)ssiReadIdeal(d);
           break;
    case 11:
           {
             res->rtyp=COMMAND;
             res->data=ssiReadCommand(l);
             int nok=res->Eval();
             if (nok) WerrorS("error in eval");
             break;
           }
    case 12: /*DEF_CMD*/
           {
             res->rtyp=0;
             res->name=(char *)ssiReadString(d);
             int nok=res->Eval();
             if (nok) WerrorS("error in name lookup");
             break;
           }
    case 13: res->rtyp=PROC_CMD;
             res->data=ssiReadProc(d);
             break;
    case 14: res->rtyp=LIST_CMD;
             res->data=ssiReadList(l);
             break;
    case 16: res->rtyp=NONE; res->data=NULL;
             break;
    case 17: res->rtyp=INTVEC_CMD;
             res->data=ssiReadIntvec(d);
             break;
    case 18: res->rtyp=INTMAT_CMD;
             res->data=ssiReadIntmat(d);
             break;
    case 19: res->rtyp=BIGINTMAT_CMD;
             res->data=ssiReadBigintmat(d);
             break;
    case 20: ssiReadBlackbox(res,l);
             break;
    case 21: ssiReadAttrib(res,l);
             break;
    // ------------
    case 98: // version
             {
                int n98_v,n98_m;
                BITSET n98_o1,n98_o2;
                n98_v=s_readint(d->f_read);
                n98_m=s_readint(d->f_read);
                n98_o1=s_readint(d->f_read);
                n98_o2=s_readint(d->f_read);
                if ((n98_v!=SSI_VERSION) ||(n98_m!=MAX_TOK))
                {
                  Print("incompatible versions of ssi: %d/%d vs %d/%d",
                                  SSI_VERSION,MAX_TOK,n98_v,n98_m);
                }
                #ifndef SING_NDEBUG
                if (TEST_OPT_DEBUG)
                  Print("// opening ssi-%d, MAX_TOK=%d\n",n98_v,n98_m);
                #endif
                si_opt_1=n98_o1;
                si_opt_2=n98_o2;
                return ssiRead1(l);
             }
    case 99: ssiClose(l); m2_end(0);
    case 0: if (s_iseof(d->f_read))
            {
              ssiClose(l);
            }
            res->rtyp=DEF_CMD;
            break;
    default: Werror("not implemented (t:%d)",t);
             omFreeSize(res,sizeof(sleftv));
             res=NULL;
             break;
  }
  // if currRing is required for the result, but lost
  // define "ssiRing%d" as currRing:
  if ((d->r!=NULL)
  && (currRing!=d->r)
  && (res->RingDependend()))
  {
    ssiSetCurrRing(d->r);
  }
  return res;
no_ring: WerrorS("no ring");
  omFreeSize(res,sizeof(sleftv));
  return NULL;
}

leftv ssiRead2	(	si_link	l,
		leftv	key
	)

BOOLEAN ssiWrite	(	si_link	l,
		leftv	v
	)

Definition at line 1373 of file ssiLink.cc.

{
  if(SI_LINK_W_OPEN_P(l)==0)
     if (slOpen(l,SI_LINK_OPEN|SI_LINK_WRITE,NULL)) return TRUE;
  ssiInfo *d = (ssiInfo *)l->data;
  d->level++;
  //FILE *fich=d->f;
  while (data!=NULL)
  {
    int tt=data->Typ();
    void *dd=data->Data();
    attr *aa=data->Attribute();
    BOOLEAN with_attr=FALSE;
    if (((*aa)!=NULL)||(data->flag!=0))
    {
      attr a=*aa;
      int n=0;
      while(a!=NULL) { n++; a=a->next;}
      fprintf(d->f_write,"21 %d %d ",data->flag,n);
      a=*aa;
    }
    if ((dd==NULL) && (data->name!=NULL) && (tt==0)) tt=DEF_CMD;
      // return pure undefined names as def

    switch(tt /*data->Typ()*/)
    {
          case 0: /*error*/
          case NONE/* nothing*/:fputs("16 ",d->f_write);
                          break;
          case STRING_CMD: fputs("2 ",d->f_write);
                           ssiWriteString(d,(char *)dd);
                           break;
          case INT_CMD: fputs("1 ",d->f_write);
                        ssiWriteInt(d,(int)(long)dd);
                        break;
          case BIGINT_CMD:fputs("4 ",d->f_write);
                        ssiWriteBigInt(d,(number)dd);
                        break;
          case NUMBER_CMD:
                          if (d->r!=currRing)
                          {
                            fputs("15 ",d->f_write);
                            ssiWriteRing(d,currRing);
                            if (d->level<=1) fputc('\n',d->f_write);
                          }
                          fputs("3 ",d->f_write);
                          ssiWriteNumber(d,(number)dd);
                        break;
          case QRING_CMD:
          case RING_CMD:fputs("5 ",d->f_write);
                        ssiWriteRing(d,(ring)dd);
                        break;
          case POLY_CMD:
          case VECTOR_CMD:
                        if (d->r!=currRing)
                        {
                          fputs("15 ",d->f_write);
                          ssiWriteRing(d,currRing);
                          if (d->level<=1) fputc('\n',d->f_write);
                        }
                        if(tt==POLY_CMD) fputs("6 ",d->f_write);
                        else             fputs("9 ",d->f_write);
                        ssiWritePoly(d,tt,(poly)dd);
                        break;
          case IDEAL_CMD:
          case MODUL_CMD:
          case MATRIX_CMD:
                        if (d->r!=currRing)
                        {
                          fputs("15 ",d->f_write);
                          ssiWriteRing(d,currRing);
                          if (d->level<=1) fputc('\n',d->f_write);
                        }
                        if(tt==IDEAL_CMD)       fputs("7 ",d->f_write);
                        else if(tt==MATRIX_CMD) fputs("8 ",d->f_write);
                        else                    fputs("10 ",d->f_write);
                        ssiWriteIdeal(d,tt,(ideal)dd);
                        break;
          case COMMAND:
                   fputs("11 ",d->f_write);
                   ssiWriteCommand(l,(command)dd);
                   break;
          case DEF_CMD: /* not evaluated stuff in quotes */
                   fputs("12 ",d->f_write);
                   ssiWriteString(d,data->Name());
                   break;
          case PROC_CMD:
                   fputs("13 ",d->f_write);
                   ssiWriteProc(d,(procinfov)dd);
                   break;
          case LIST_CMD:
                   fputs("14 ",d->f_write);
                   ssiWriteList(l,(lists)dd);
                   break;
          case INTVEC_CMD:
                   fputs("17 ",d->f_write);
                   ssiWriteIntvec(d,(intvec *)dd);
                   break;
          case INTMAT_CMD:
                   fputs("18 ",d->f_write);
                   ssiWriteIntmat(d,(intvec *)dd);
                   break;
          case BIGINTMAT_CMD:
                   fputs("19 ",d->f_write);
                   ssiWriteBigintmat(d,(bigintmat *)dd);
                   break;
          default:
            if (tt>MAX_TOK)
            {
              blackbox *b=getBlackboxStuff(tt);
              fputs("20 ",d->f_write);
              b->blackbox_serialize(b,dd,l);
            }
            else
            {
              Werror("not implemented (t:%d, rtyp:%d)",tt, data->rtyp);
              d->level=0;
              return TRUE;
            }
            break;
    }
    if (d->level<=1) { fputc('\n',d->f_write); fflush(d->f_write); }
    data=data->next;
  }
  d->level--;
  return FALSE;
}