[Gambas-user] Problem with the EXEC[] function

[Benoit Minisini]

On Monday 07 March 2005 16:30, Rolf Schmidt wrote:
> Thank you Benoit Minisini:
> > > PUBLIC DBisCreated AS Boolean
> > >
> > > PUBLIC SUB Process_Read()
> > >   DIM sline AS String
> > >
> > >   LINE INPUT #LAST, sline
> > > '  message.Info(sline)
> > >
> > >   returndata = returndata & sline
> > >   IF sline = "CREATE DATABASE" THEN
> > >     DBisCreated = TRUE
> > >   ELSE
> > >     DBisCreated = FALSE
> > >   ENDIF
> > > END
> > >
> > > PUBLIC FUNCTION createDB() AS Boolean
> > >   CAskDB.ShowModal()
> > >   EXEC ["createdb", "-h", FHV.konfig.Key("host"), "-U",
> > >             FHV.konfig.Key("user"), "-E", "UNICODE",
> > >             FHV.konfig.Key("database")] WAIT FOR READ
> > > ' why is the flag always false?
> > >   IF DBisCreated = TRUE THEN
> > >     EXEC ["psql", "-h", FHV.konfig.Key("host"), "-u",
> > > FHV.konfig.Key("user"), "-d", FHV.konfig.Key("database"), "-f",
> > >              "/home/entwicklung/hausverwaltung/HV/pgdatabase"] WAIT FOR
> > > READ ' why does this function never comes back - could it be, that it
> > > sends some ' informations via the error chanel? - How can I fetch these
> > > too? ENDIF
> > > END
> >
> > This is a problem in the process management of Gambas. You must not use
> > WAIT if you want to use FOR READ/WRITE, because the event loop is not
> > called.
>
> But without the WAIT statement the flag will never be TRUE.

You must wait by yourself:

DIM hProcess AS Process

EXEC ["createdb", "-h", FHV.konfig.Key("host"), "-U",
            FHV.konfig.Key("user"), "-E", "UNICODE",
            FHV.konfig.Key("database")] WAIT FOR READ AS hProcess

WHILE hProcess.State = hProcess.Running
  WAIT 0.1
WEND

But this is not a clean way. A better way is to manage everything around the 
top event loop: running the first process in Form_Load, for example, and 
running the second process in Process_Kill() when the first is terminated.

Another point: at the moment, you cannot manage completely programs that need 
to be run in a terminal (like /bin/sh, or telnet).

Regards,

-- 
Benoit Minisini
mailto:gambas at ...1...