amd64/128259: "`" crashes csh

Nate Eldredge neldredge at
Tue Oct 21 04:33:34 UTC 2008

On Tue, 21 Oct 2008, Jack Low wrote:

>> Description:
> If you type "`" in the csh shell, the shell crashes
>> How-To-Repeat:
> Type "`" and hit enter.
>> Fix:

Thanks for the report, Jack.

I suspect this is related to bin/125185, which involved csh improperly 
messing with global state in a vfork'ed subshell.  Note that for both the 
present bug and 125185, the crash does not occur if csh is run with -F to 
use fork() instead of vfork().

nate at vulcan:/usr/home/nate$ csh
Unmatched `.
Segmentation fault: 11 (core dumped)
nate at vulcan:/usr/home/nate$ csh -F
Unmatched `.

I'll repeat my recommendation from 125185 that -F be made the default, so 
that vfork() is not used.

I doubt that this bug is amd64 specific but don't have another machine to 
make sure at the moment.  Probably it should be reclassified as "bin". 
It's also present in 7.0-RELEASE, by the way.


Nate Eldredge
neldredge at

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