The Problem:
I have a good working expect script which runs fine on
SunOS 4.1.3, Solaris 2.5.1, and Suse Linux 6.2.
This script spawns a telnet to another machine, logs in,
and executes some commands.
When I run the exact same expect script on my brand new
Dell PIII 450 PowerEdge Server "big ole honkin' PC" running
Dell factory-installed RedHat 6.0, the script dumps core.

The Investigation:
1. Expect's internal debugging is not much help. It gives:
spawn telnet 145.1.1.12
parent: waiting for sync byte
parent: telling child to go ahead
parent: sync byte write: broken pipe


2. I run "gdb /usr/bin/expect core" on the core file and I
get
the following output:
*********************************************
Copyright 1998 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-redhat-linux"...
(no debugging symbols found)...

warning: core file may not match specified executable file.
Core was generated by `expect -- ./sms_message.exp'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /usr/lib/libexpect5.28.so...
(no debugging symbols found)...done.
Reading symbols from /usr/lib/libtcl8.0.so...done.
Reading symbols from /lib/libdl.so.2...done.
Reading symbols from /lib/libm.so.6...done.
Reading symbols from /lib/libutil.so.1...done.
Reading symbols from /lib/libc.so.6...done.
Reading symbols from /lib/ld-linux.so.2...done.
#0  0x40106fea in _IO_vfprintf (s=0xbfff9f68,
    format=0x4003481d "ioctl(%s,I_PUSH,\"ptem\") = %s\n",
ap=0xbfffc6e4)
    at vfprintf.c:1248
vfprintf.c:1248: No such file or directory.
(gdb)
*********************************************

3. I am not familiar with the I_PUSH flag, so I search for
it in /usr/src/linux-2.2.5:
find /usr/src/linux-2.2.5 -follow -type f -exec grep -l
I_PUS
H {} \;
/usr/src/linux-2.2.5/arch/sparc64/solaris/ioctl.c
/usr/src/linux-2.2.5/drivers/sgi/char/streamable.c
/usr/src/linux-2.2.5/ibcs/ChangeLog
/usr/src/linux-2.2.5/ibcs/devtrace/devtrace.c
/usr/src/linux-2.2.5/ibcs/iBCSemul/ioctl.c

The only references I find are for Sparc64 and SGI, but
I'm running on Intel!! I'm ignoring the ibcs stuff, because
I'm running expect scripts...


4. I run "strace -o strace.out ./sms_message.exp, and it
says (down at the end of the output) :
*********************************************
open("/dev/ptmx", O_RDWR)               = 7
ioctl(7, TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(7, 0x80045430, 0xbffff258)        = 0
stat("/dev/pts/3", {st_mode=S_IFREG|S_ISUID|03, st_size=0,
...}) = 0
ioctl(7, 0x40045431, 0xbffff2e4)        = 0
ioctl(7, TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(7, 0x80045430, 0xbfffe1f0)        = 0
stat("/dev/pts/3", {st_mode=S_IFREG|S_ISUID|03, st_size=0,
...}) = 0
statfs("/dev/pts/3", {f_type=0x1cd1, f_bsize=1024,
f_blocks=0, f_bfree=0, f_file
s=0, f_ffree=0, f_namelen=255}}) = 0
fcntl(7, F_SETFD, FD_CLOEXEC)           = 0
pipe([8, 9])                            = 0
pipe([10, 11])                          = 0
pipe([12, 13])                          = 0
fork()                                  = 2435
close(9)                                = 0
close(10)                               = 0
close(13)                               = 0
write(5, "parent: waiting for sync byte\r\n"..., 31) = 31
write(2, "parent: waiting for sync byte\r\n"..., 31) = 31
write(6, "parent: waiting for sync byte\r\n"..., 31) = 31
read(8, "", 1)                          = 0
--- SIGCHLD (Child exited) ---
write(5, "parent: telling child to go ahea"..., 35) = 35
write(2, "parent: telling child to go ahea"..., 35) = 35
write(6, "parent: telling child to go ahea"..., 35) = 35
write(11, " ", 1)                       = -1 EPIPE (Broken
pipe)
--- SIGPIPE (Broken pipe) ---
write(2, "parent: sync byte write: broken "..., 38) = 38
write(5, "parent: sync byte write: broken "..., 38) = 38
write(6, "parent: sync byte write: broken "..., 38) = 38
_exit(-1)                               = ?
*********************************************

Looks like the forked child died quick??



At this point my best guess is:
I have a binary compiled for either Sun's or SGI's
particular way of handling ptys for telnet.


Even weirder? - when I run expect from the command line
and spawn a telnet, it works!!


So I'm out of my depth here. Can you help???
I'll be happy to provide more traces, captures, whatever.


By the way, I'm reporting this to RedHat because I thought
you might be interested in how a brand new Dell-installed
Linux system behaves, and my hope is that you back your
entire product as well as your reputation would indicate.

We're going to use this system to
network-manage a whole bunch of Sun machines, routers, and
Tandem machines - it's a fairly high-profile project and
my little butt is somewhat on the line. Help Help Help!!!

Thanks,
Bill Rasco
cwr001.com
847.538.4821





Here's some version info...

expect1.1> expect_version
5.28.1
                                                     uname
-a
Linux sapphire.iden_lab.comm.mot.com 2.2.5-15smp #1 SMP Mon
Apr 19 22:43:28 EDT
1999 i686 unknown

% info tclversion
8.0
%




------- Additional Comments From   10/12/99 14:38 -------
Update:
I acquired tcl8.0 and expect5.31 from their respective sites and
built them. Now my script works fine.
I guess this bug report now turns into a "fix the distribution"
report.
Anyways, I'm happy. Just be aware that RedHat 6.0 as shipped from
Dell factory on PowerEdge Server has a bug that dumps core when
"expect" program attempts to spawn a telnet from a script.

Bill