dash -n and -v not implemented?

dash -n and -v not implemented?

[Adam Kellas]

Am I missing something, or do the -n and -v flags have no effect? The 
following compares the behavior of bash, ksh, and dash (bash requires an 
extra flag to suppress startup files):

% ksh -v -n -c uname
uname

% bash --norc -v -n uname
uname

% dash -v -n -c uname
Linux

AK

Re: dash -n and -v not implemented?

[Eric Blake]

On 08/23/2010 01:47 PM, Adam Kellas wrote:
> Am I missing something, or do the -n and -v flags have no effect? The
> following compares the behavior of bash, ksh, and dash (bash requires an
> extra flag to suppress startup files):
>
> % ksh -v -n -c uname
> uname
>
> % bash --norc -v -n uname
> uname
>
> % dash -v -n -c uname
> Linux

POSIX states that an interactive shell may ignore 'set -n'; and by 
extension, 'sh -n' can be a no-op if the shell would otherwise be 
interactive.  But your example is not an interactive shell; and POSIX is 
clear that both -v and -n must have the same effect as an option to the 
shell command line as they would have to a use of set within the shell.

I think the absence of handling for both of these options is a definite 
bug according to POSIX rules on sh.

-- 
Eric Blake   eblake@redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org