Thank you for this bug report. To properly diagnose the problem, we
need a backtrace to see what is happening behind the scenes. To
find out how to generate a backtrace, please read
http://bugs.php.net/bugs-generating-backtrace.php

Once you have generated a backtrace, please submit it to this bug
report and change the status back to "Open". Thank you for helping
us make PHP better.

A backtrace really would help for us...

Derick

The "Edit Submission" form said I wan't allowed to change the state to Open, so I added a comment here.

Here's a script to trigger the segfault:

<?
        $ds = array(
                0 => array("pipe", "r"),
                1 => array("pipe", "w"),
                2 => array("file", "/tmp/stderr")
        );

        $cat = proc_open(
                "/bin/cat",
                $ds,
                $pipes
        );

        echo "I didn't segfault!\n";
?>

And here's a backtrace:

kims@lionred:~/public_html$  gdb /usr/local/bin/php core
GNU gdb 2002-04-01-cvs
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-linux"...
Core was generated by `/usr/local/bin/php sf.php'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /lib/libcrypt.so.1...done.
Loaded symbols for /lib/libcrypt.so.1
Reading symbols from /lib/libresolv.so.2...done.
Loaded symbols for /lib/libresolv.so.2
Reading symbols from /lib/libm.so.6...done.
Loaded symbols for /lib/libm.so.6
Reading symbols from /lib/libdl.so.2...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /lib/libpthread.so.0...done.
Loaded symbols for /lib/libpthread.so.0
Reading symbols from /lib/libc.so.6...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
#0  0x080c3c03 in zif_proc_open (ht=3, return_value=0x820e910, this_ptr=0x0, 
    return_value_used=1, tsrm_ls=0x81d55e0)
    at /home/kims/php4/ext/standard/exec.c:800
800					convert_to_string_ex(zmode);
(gdb) bt
#0  0x080c3c03 in zif_proc_open (ht=3, return_value=0x820e910, this_ptr=0x0, 
    return_value_used=1, tsrm_ls=0x81d55e0)
    at /home/kims/php4/ext/standard/exec.c:800
#1  0x081674b9 in execute (op_array=0x8209a08, tsrm_ls=0x81d55e0)
    at /home/kims/php4/Zend/zend_execute.c:1587
#2  0x08152d1f in zend_execute_scripts (type=8, tsrm_ls=0x81d55e0, retval=0x0, 
    file_count=3) at /home/kims/php4/Zend/zend.c:810
#3  0x08125b2a in php_execute_script (primary_file=0xbffffd38, 
    tsrm_ls=0x81d55e0) at /home/kims/php4/main/main.c:1373
#4  0x0816fedb in main (argc=2, argv=0xbffffdb4)
    at /home/kims/php4/sapi/cli/php_cli.c:622
(gdb) 

Thankyou :)

Fixed in CVS now, update your tree or wait for a new snapshot (snaps.php.net).
This fix will be in PHP 4.3.0.

Derick