Re: Bug#112424: zsh: zsh can't read from /proc

Re: Bug#112424: zsh: zsh can't read from /proc

[Clint Adams]

Do we want to special-case this?

> zsh seems to have trouble reading from /proc special files.
> For example:
> 
> bzzrt:/home/wsl% read HOST </proc/sys/kernel/hostname
> 1 b:/home/wsl% cat /proc/sys/kernel/hostname | read HOST
> bzzrt:/home/wsl%
> 
> After the first command, $HOST is set to "b" and the return code of
> the command is 1 (my prompt is configured to show this). When using
> cat everything is fine, and $HOST is once again set to the proper
> host name ("bzzrt").
> 
> The problem is that zsh reads files one byte at a time. This is
> perfectly legitimate of course, but Linux does not seem to support
> that for /proc files. An acceptable workaround for Linux' poor
> performance would be to fstat(stdin) and use a large read if stat
> reports a zero file size (and the file is a plain file).
> 
> Of course, the real location to fix this would be the Linux kernel.

Re: Bug#112424: zsh: zsh can't read from /proc

[Bart Schaefer]

On Sep 17, 11:34am, Clint Adams wrote:
} Subject: Re: Bug#112424: zsh: zsh can't read from /proc
}
} Do we want to special-case this?
} 
} > zsh seems to have trouble reading from /proc special files.
} > 
} > The problem is that zsh reads files one byte at a time.

Hrm.  There's always

    read -u0 -k 128 HOST </proc/sys/kernel/hostname

but that has the drawback of returning a nonzero $?.

In any case, it appears that bash and bash2 have the same behavior when
reading from that file, so I'd say this is not our bug to fix.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

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