The reason is that in unix you have to call wait() or waitpid() 
from libc to collect the return status of the child process. If not 
done so than the process will remain as zombie in the process 
table. Find below a patch introducing a expect_pclose() function 
to php-expect which closes the stream and calls waitpid(). 
 
If there is allready a expect_pclose() funciton or a RSHUTDOWN 
funcition doing this , why is it not included in the latests version 
0.2.4 ??? 
--------------------------------------------------------------------------------- 
diff -bBd -u expect-0.2.4_a/config.m4 expect-0.2.4/config.m4 
--- expect-0.2.4_a/config.m4    2007-09-09 17:43:36.000000000 
+0200 
+++ expect-0.2.4/config.m4      2008-06-12 16:16:20.000000000 
+0200 
@@ -1,5 +1,5 @@ 
 dnl 
-dnl $Id: config.m4,v 1.4 2007/09/09 15:43:36 michael Exp $ 
+dnl $Id: config.m4,v 1.1 2008/06/12 14:16:20 hintermueller Exp $ 
 dnl 
 
 PHP_ARG_WITH(expect,for expect support, 
diff -bBd -u expect-0.2.4_a/expect.c expect-0.2.4/expect.c 
--- expect-0.2.4_a/expect.c     2007-10-20 09:13:09.000000000 
+0200 
+++ expect-0.2.4/expect.c       2008-07-17 19:13:52.000000000 
+0200 
@@ -21,11 +21,14 @@ 
 #include "php_expect.h" 
 #include <string.h> 
 #include <errno.h> 
+#include <sys/types.h> 
+#include <sys/wait.h> 
 
 /* {{{ expect_functions[] */ 
 function_entry expect_functions[] = { 
        PHP_FE(expect_popen,    NULL) 
        PHP_FE(expect_expectl,  third_arg_force_ref) 
+       PHP_FE(expect_pclose,   NULL) 
        { NULL, NULL, NULL } 
 }; 
 /* }}} */ 
@@ -153,6 +156,27 @@ 
 
 
 /* {{{ 
+ * proto resource expect_pclose (string command) 
+ */ 
+PHP_FUNCTION(expect_pclose) 
+{ 
+ 
+    zval *z_stream; 
+       php_stream *stream; 
+       int command_len; 
+ 
+       if (ZEND_NUM_ARGS() != 1) { 
+        WRONG_PARAM_COUNT; 
+    } 
+       if (zend_parse_parameters (ZEND_NUM_ARGS() 
TSRMLS_CC, "r", &z_stream) == FAILURE) { 
+               RETURN_FALSE; 
+       } 
+       php_stream_from_zval (stream, &z_stream); 
+    php_stream_close(stream); 
+    waitpid(-1,NULL,WUNTRACED); 
+    RETURN_TRUE; 
+} 
+/* {{{ 
  * proto resource expect_popen (string command) 
  */ 
 PHP_FUNCTION(expect_popen) 
diff -bBd -u expect-0.2.4_a/expect_fopen_wrapper.c 
expect-0.2.4/expect_fopen_wrapper.c 
--- expect-0.2.4_a/expect_fopen_wrapper.c       2007-10-19 
20:52:39.000000000 +0200 
+++ expect-0.2.4/expect_fopen_wrapper.c 2008-06-12 
16:16:21.000000000 +0200 
@@ -16,7 +16,7 @@ 
   +----------------------------------------------------------------------+ 
 */ 
 
-/* $Id: expect_fopen_wrapper.c,v 1.2 2007/09/09 15:43:36 
michael Exp $ */ 
+/* $Id: expect_fopen_wrapper.c,v 1.1 2008/06/12 14:16:21 
hintermueller Exp $ */ 
 
 #include "php.h" 
 #include "php_expect.h" 
diff -bBd -u expect-0.2.4_a/php_expect.h 
expect-0.2.4/php_expect.h 
--- expect-0.2.4_a/php_expect.h 2007-10-20 08:42:20.000000000 
+0200 
+++ expect-0.2.4/php_expect.h   2008-07-17 19:13:58.000000000 
+0200 
@@ -46,6 +46,7 @@ 
 PHP_MINFO_FUNCTION(expect); 
 
 PHP_FUNCTION(expect_popen); 
+PHP_FUNCTION(expect_pclose); 
 PHP_FUNCTION(expect_expectl); 
 
 extern php_stream_wrapper php_expect_wrapper; 
------------------------------------------------------------------------ 
 
NOTE: this is only tested in linux/bsd/unix and alike. Do know 
nothing about windows. 
 
Where shall i send the patch to because copying form the web is 
not the best solution.

Sorry misspelled email address

There's a stream close handler that should do the job, and it's included into 0.2.4 release:

static int php_expect_stream_close (php_stream_wrapper *wrapper, php_stream *stream TSRMLS_DC)
{
    zval* z_pid = stream->wrapperdata;
    int s = 0;
    waitpid (Z_LVAL_P(z_pid), &s, 0);
    zval_ptr_dtor (&z_pid);
    stream->wrapperdata = NULL;
    return s;
}

This should work fine if you close the stream using fclose().

No feedback was provided. The bug is being suspended because
we assume that you are no longer experiencing the problem.
If this is not the case and you are able to provide the
information that was requested earlier, please do so and
change the status of the bug back to "Open". Thank you.

The thing is that stream wrapper is only called for code such like:

$stream=fopen("expect://telnet askjfddfdsf", "rw");
fclose($stream);

but is never called for code like in original example:

$stream=expect_popen("telnet -l $os_user $host_ip");
fclose($stream);

so the bug still exists.

php-pecl-expect-0.3.1