popen leads to a sh<defunct>

[dhina]

Hi
Im using popen call, which in turn forks, invokes a shell and ties one end of pipe to it. Fine, but even after pclose-ing the dead shell is not reaped out by main.
But man pages say pclose does a wait4. I badly need to get rid of that sh<defunct>. Below is snap shot of code what I do.

            .
            .
	sprintf(arg,"pidof %s",process);

	/* Clearing out buffer */
	fflush(stdout);
	if((file_fp = popen(arg,"r")) == NULL)
	{
		printf(" Unable to find the Pid ");
		return FAILURE;
	}

	fgets(pid,10,file_fp);
	proc_pid = atoi(pid);
	if(pclose(file_fp) != 0)
	{
	         printf("Failed to close pipe\n");
	}
             .
             .

Can someone help me out to fix this issue.

[wje_lf]

When I run this program:

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define process "bash"

int main(void)
{
  int   dummy;
  int   jndex;

  char  arg[80];
  char  pid[80];

  FILE *file_fp;

  /* Create a defunct process so we can see how they look. */

  dummy=fork();

  if(dummy==-1)
  {
    perror("fork");

    exit(1);
  }

  if(dummy==0)
  {
    exit(0);
  }

  printf("This is how a defunct process looks:\n");

  fflush(stdout);

  system("ps -ef | grep defunct | grep -v grep | grep -v ps");

  sprintf(arg,"/sbin/pidof %s",process);

  printf("This is the object command:\n%s\n",
         arg
        );

  printf("This is the output of the object command:\n");

  fflush(stdout);

  system(arg);

  if((file_fp=popen(arg,"r"))==NULL)
  {
    perror("popen()");

    exit(1);
  }

  fgets(pid,sizeof(pid),file_fp);

  if(pclose(file_fp)!=0)
  {
    perror("pclose()");

    exit(1);
  }

  printf("Any additional defunct processes?\n");

  fflush(stdout);

  system("ps -ef | grep defunct | grep -v grep | grep -v ps");

  printf("The acid test.\n");

  for(jndex=0;
      jndex<10;
      jndex++
     )
  {
    if((file_fp=popen(arg,"r"))==NULL)
    {
      perror("popen()");

      exit(1);
    }

    fgets(pid,sizeof(pid),file_fp);

    if(pclose(file_fp)!=0)
    {
      perror("pclose()");

      exit(1);
    }
  }

  printf("Any additional defunct processes?\n");

  fflush(stdout);

  system("ps -ef | grep defunct | grep -v grep | grep -v ps");

  return 0;

} /* main() */

I get this:

This is how a defunct process looks:
wally    26985 26984  0 01:27 pts/19   00:00:00 [t <defunct>]
This is the object command:
/sbin/pidof bash
This is the output of the object command:
20191 31245 31236 31222 31039 31030 31021 30950 30941 30932
Any additional defunct processes?
wally    26985 26984  0 01:27 pts/19   00:00:00 [t <defunct>]
The acid test.
Any additional defunct processes?
wally    26985 26984  0 01:27 pts/19   00:00:00 [t <defunct>]

What do you get when you run this exact program? (You may have to change the path of pidof if it's not in /sbin on your system.)