From bug-octave-request at bevo dot che dot wisc dot edu  Thu Oct  8 14:06:47 1998
Subject: Unidentified subject!
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: john <john at arrows dot demon dot co dot uk>
Cc: bug-octave at bevo dot che dot wisc dot edu
Date: Thu, 8 Oct 1998 14:06:37 -0500 (CDT)

On  5-Jul-1998, john <john at arrows dot demon dot co dot uk> wrote:

| To: bug-octave at bevo dot che dot wisc dot edu
| Cc: john at arrows dot demon dot co dot uk
| Subject: closeplot failing after popen or system(xv,0,async)
| 
| Bug report for Octave 2.0.13 configured for i586-pc-linux-gnulibc1
| 
| Description:
| -----------
| 
| As previously reported, the sequence
| 
|    octave:1> sombrero(10)
|    octave:2> system("xv", 0, "async" ) ;
|    octave:3> closeplot
| 
| causes octave to wait until the "xv" process completes.or
| 
| Similarly, 
| 
|    octave:1> sombrero(10)
|    octave:2> popen("sort", "w");
|    octave:3> closeplot
| 
| causes octave to wait, probably until the "sort" is terminated.

Please try the following patch.

This problem had me stumped for quite a while.  I think all that is
really required is the addition of sending "quit" to gnuplot before
deleting the plot_stream object, but I think the other changes to the
octave_procbuf and procstream classes are good too, just to clean
things up a bit.

Thanks,

jwe

Thu Oct  8 13:47:55 1998  John W. Eaton  <jwe at bevo dot che dot wisc dot edu>

	* oct-procbuf.h (octave_procbuf::wstatus): New data member.
	Initialize in constructors.
	(octave_procbuf::wait_status): New member function.
	* oct-procbuf.cc (octave_procbuf::sys_close): Use class data
	member wstatus, not local variable.
	* procstream.cc (procstreambase::close): Don't call sys_close directly.
	Get subprocess exit status by calling wait_status for our procbuf.
	* pt-plot.cc (close_plot_stream): Send "quit" command to gnuplot
	before deleting plot_stream.


*** src/oct-procbuf.h~	Tue Apr 28 14:08:01 1998
--- src/oct-procbuf.h	Wed Oct  7 13:29:32 1998
***************
*** 38,47 ****
  public:
  
    octave_procbuf (void)
!     : filebuf (), proc_pid (-1), next (0) { }
  
    octave_procbuf (const char *command, int mode)
!     : filebuf (), proc_pid (-1), next (0) { open (command, mode); }
  
    ~octave_procbuf (void) { close (); }
  
--- 38,48 ----
  public:
  
    octave_procbuf (void)
!     : filebuf (), wstatus (-1), proc_pid (-1), next (0) { }
  
    octave_procbuf (const char *command, int mode)
!     : filebuf (), wstatus (-1), proc_pid (-1), next (0)
!   { open (command, mode); }
  
    ~octave_procbuf (void) { close (); }
  
***************
*** 52,60 ****
--- 53,65 ----
  
    virtual int sys_close (void);
  
+   int wait_status (void) const { return wstatus; }
+ 
    pid_t pid (void) { return proc_pid; }
  
  protected:
+ 
+   int wstatus;
  
    pid_t proc_pid;
  
*** src/oct-procbuf.cc~	Wed May 13 23:07:34 1998
--- src/oct-procbuf.cc	Thu Oct  8 00:48:11 1998
***************
*** 146,153 ****
  {
  #if defined (HAVE_SYS_WAIT_H)
  
-   int wstatus;
- 
    pid_t wait_pid;
  
    int status = -1;
--- 146,151 ----
*** src/procstream.h~	Sun Apr 28 04:00:07 1996
--- src/procstream.h	Wed Oct  7 21:13:47 1998
***************
*** 78,86 ****
    ~iprocstream (void) { }
  
    void open (const char *name, int mode=ios::in)
!     {
!       procstreambase::open (name, mode);
!     }
  
  private:
  
--- 78,84 ----
    ~iprocstream (void) { }
  
    void open (const char *name, int mode=ios::in)
!     { procstreambase::open (name, mode); }
  
  private:
  
***************
*** 102,110 ****
    ~oprocstream (void) { }
  
    void open (const char *name, int mode=ios::out)
!     {
!       procstreambase::open(name, mode);
!     }
  
  private:
  
--- 100,106 ----
    ~oprocstream (void) { }
  
    void open (const char *name, int mode=ios::out)
!     { procstreambase::open(name, mode); }
  
  private:
  
***************
*** 123,135 ****
    procstream (const char *name, int mode)
      : procstreambase(name, mode) { }
  
- 
    ~procstream (void) { }
  
    void open (const char *name, int mode)
!     {
!       procstreambase::open(name, mode);
!     }
  
  private:
  
--- 119,128 ----
    procstream (const char *name, int mode)
      : procstreambase(name, mode) { }
  
    ~procstream (void) { }
  
    void open (const char *name, int mode)
!     { procstreambase::open(name, mode); }
  
  private:
  
*** src/procstream.cc~	Sat Mar  2 19:45:43 1996
--- src/procstream.cc	Wed Oct  7 13:30:14 1998
***************
*** 54,63 ****
  
    if (is_open ())
      {
-       status = pb.sys_close ();
- 
        if (! pb.close ())
  	set (ios::failbit);
      }
  
    return status;
--- 54,63 ----
  
    if (is_open ())
      {
        if (! pb.close ())
  	set (ios::failbit);
+ 
+       status = pb.wait_status ();
      }
  
    return status;
*** src/pt-plot.cc~	Wed Apr 15 01:19:36 1998
--- src/pt-plot.cc	Thu Oct  8 13:49:10 1998
***************
*** 909,914 ****
--- 909,915 ----
  
    if (plot_stream)
      {
+       send_to_plot_stream ("\nquit\n");
        delete plot_stream;
        plot_stream = 0;
      }