Conference bulova::decw_jan-89_to_nov-90

2842.0. "CREATE/TERMINAL from a subprocess" by TMIS01::DORON (Doing my BEST !!!) Thu May 31 1990 07:11

Hi,

 I have tried to CREATE/TERMINAL from a subprocess that was created by an IMAGE
(using the LIB$SPAWN command). The result was that the new terminal window
appeared for a while and then disappeared (without giving any message). When I
gave the command CREATE/TERMINAL/DETACH it worked fine and when I gave the
command CREATE/TERMINAL/NOPROCESS it opened a new window and asked for Username
(as expected). I enclose a small C program that calls LIB$SPAWN and waits
without prompt for your input (just enter the DCL command U wish to be
performed). The question is, why does it happen when while trying to
CREATE/TERMINAL and let it be opend as another subprocess?

-------------------------------Cut Here----------------------------------------
/*
*
* Run the program and give it any dcl command you like
* create/terminal .....
* does not work.
* edit/tpu/disp=decw
* works fine.
*
*/



#include <clidef.h>
#include <descrip.h>

typedef char *string;
#define EOS '\0'
char spawn_cmd_error[80];

int
  spawn_command(command)
string command;
{
  struct dsc$descriptor_s cmddesc;
  struct dsc$descriptor_s prmdesc;
  int status, real_status;
  int sa;
  char	mes_l[80+1];
  char	err_msg[80+1];
  char	str[256];
  static	$DESCRIPTOR(STR,"");
  unsigned short m_len;
  int i,s;
  double x;
  string serr;
  static int event_flag= -1; 
  
  str[0] = EOS;
  if(event_flag == -1){
    if(!((s = lib$get_ef(&event_flag)) & 1)){
    STR.dsc$a_pointer = str;
    STR.dsc$w_length = 256;
    sys$getmsg(s,&m_len,&STR,15,0);
    str[m_len]=EOS;
    strcpy(spawn_cmd_error,str);
    return s;
    }
  } 
  cmddesc.dsc$w_length=strlen(command);
  cmddesc.dsc$a_pointer=command;
  cmddesc.dsc$b_class=DSC$K_CLASS_S;
  cmddesc.dsc$b_dtype=DSC$K_DTYPE_T;
  status = lib$spawn(&cmddesc,0,0,/*&CLI$M_NOWAIT*/0,0,0,&real_status,&event_flag,
                     0,0,0,0);
  if(!((s=sys$waitfr(event_flag)) & 1)){
    STR.dsc$a_pointer = str;
    STR.dsc$w_length = 256;
    sys$getmsg(s,&m_len,&STR,15,0);
    str[m_len]=EOS;
    strcpy(spawn_cmd_error,str);
     return s;
  }

  if ( (!( status & 1 )) || (!( real_status & 1 )) ) {
    if ( ! ( status & 1)  )
      sa=status;
    else
      sa=real_status;
    STR.dsc$a_pointer = str;
    STR.dsc$w_length = 256;
    s = sys$getmsg(sa,&m_len,&STR,15,0);
    str[m_len]=EOS;
  }
  strcpy(spawn_cmd_error,str);
  if ( ! ( status & 1)  )
    return status;
  else
    return real_status;
}

 

main()
{
char buf[100];
for(;;){
gets(buf);
printf("%s\n",buf);
printf(" %d %s\n",spawn_command(buf),spawn_cmd_error);
}
}

    This sounds like the same problem often encountered when using
    CREATE/TERMINAL for applications started from the Session Manager.
    Basically, CREATE/TERMINAL does not wait for the created process to
    end (i.e. it's like SPAWN/NOWAIT).