program pipes;
{---------------------------------------------------------------}
{ pipes - change parameters of spooler driver
{
{ date : 13-Feb-1984
{ file : pipes.text
{
{ Keith Ball
{ last modified : 13-Feb-1984
{
{---------------------------------------------------------------}
const
    pgmname =  'Pipes';
    vrsn    =  '1.0a';
    date    =  '13-Feb-1984';

    SpoolDrv = 3;            {spooler driver unit number}

    {function codes to unitstatus functions of driver}
    ChngPiName = 18;         {change pipe name}
    CloseFunc  = 19;         {close pipe}
    ChngMessg  = 20;         {change message}
    SlotServer = 21;         {change slot and server numbers}

type
    str40: string[40];

var
    i: integer;
    s: string[120];

procedure DoClose;
    var ior: integer;
    begin
    unitstatus(SpoolDrv,ior,CloseFunc); ior := ioresult;
    if ior <> 0 then writeln('Pipe close failed.  Error = ',ior);
    end;

procedure CallDriver(fnccode: integer; errmsg: str40;);
    var ior,eq: integer;
    begin
    eq := pos('=',s);
    if (eq = 0) or (eq+1 >= length(s)) then exit(CallDriver);

    s := copy(s,eq+1,length(s));

    unitstatus(SpoolDrv,s,fnccode); ior := ioresult;
    if ior <> 0 then writeln(errmsg,'  Error = ',ior);
    end;

procedure DoMessage;
    begin
    CallDriver(ChngMessg,'Message change failed.');
    end;

procedure DoPipeName;
    begin
    CallDriver(ChngPiName,'Pipe name change failed.');
    end;

function ConvertInt(st: str40): integer;
    begin
    temp := 0; i := 1; Stop := FALSE;
    while (i <= length(st)) and (NOT Stop) do begin
        if (st[i] >= '0') and (st[i] <= '9') then
           temp := (temp * 10) + (ord(st[i]) - ord('0'))
        else
           Stop := TRUE;
        i := i + 1;
        end;
    if Stop then ConvertInt := -1
            else ConvertInt := temp;
    end;

procedure DoServerSlot;
    var i,eq,l: integer
        slt,srv: str40;
        ss: record
              slot,server: integer;
              end;
    begin
    eq := pos('=',s);
    if (eq = 0) or (eq+1 >= length(s)) then exit(DoServerSlot);

    s := copy(s,eq+1,length(s));
    l := pos('/',s);
    if (l = 0) then l := length(s);
    slt := copy(s,1,l);

    if (l+1 < length(s)) then srv := copy(s,l+1,length(s))
                         else srv := '';

    with ss do begin
        slot   := ConvertInt(slt);
        if (slot < 1) or (slot > 5) then begin
           writeln('Invalid slot number :  ',slt);
           exit(DoServerSlot);
           end;

        server := ConvertInt(srv);
        if (server < 0) or (slot > 63) then begin
           writeln('Invalid server number :  ',srv);
           exit(DoServerSlot);
           end;
        end;

    unitstatus(SpoolDrv,ss,SlotServer); ior := ioresult;
    if ior <> 0 then writeln('Slot/Server number change failed.'
                                        Error = ',ior);
    end;

begin
if argc = 0 then begin
   writeln(pgmname,' - ',vrsn,'  ',date);
   writeln('Valid command line parameters :');
   writeln('   close - close the current pipe.');
   writeln('   m=    - change the message to what follows =.');
   writeln('   n=    - change the pipe name to what follows =.');
   writeln('   s=    - change the slot/server numbers to what follows =.');
   writeln;
   writeln('Examples :');
   writeln('   pipes m=This_is_a_message');
   writeln('   pipes n=NEC');
   exit(pipes);
   end;

for i := 1 to argc do begin
    s := argv[i]^;
    if (s[1] >= 'a') and (s[1] <= 'z') then s[1] := chr(ord(s[1]) - $20);
         if (s[1] = 'C') then DoClose
    else if (s[1] = 'M') then DoMessage
    else if (s[1] = 'N') then DoPipeName
    else if (s[1] = 'S') then DoServerSlot;
    end;
end.