Thanks all.
Now I got it:
The point is the action on bash-4.2 and before deosn't match the action on ksh
and zsh.
Jianhong
发自网易邮箱手机版
在2017年11月27日 23:42，Vladimir Marek 写道：
> > It's not the point. the problem is bash-4.4 auto add quote around $var or
> > $(cmd) after '<<<'
> >
> > On bash-4.2 and before following command always works fine
> > read ignore fstype <<<$(df --output=fstype $mountpoint)
> >
> > But after Update bash-4.4, our customer's script get fail, do you
> > understand what I mean?
>
> The script is broken. It happened to work in bash 4.2 because of a bug
> in bash 4.2 that cancelled out the bug in the script.
>
> wooledg:~$ df --output=fstype /
> Type
> ext4
>
> Here is how the script should be written:
>
> { read; read -r fstype; } < <(df --output=fstype "$mountpoint")
>
> And testing it:
>
> wooledg:~$ mountpoint=/
> wooledg:~$ { read; read -r fstype; } < <(df --output=fstype "$mountpoint")
> wooledg:~$ declare -p fstype
> declare -- fstype="ext4"
Or even
fstype=$( stat --file-system --print "%T\n" "$mountpoint" )
--
Vlad
