On 2021-10-30 14:33:04 +0100, Stephane Chazelas via austin-group-l at The Open
Group wrote:
> POSIX ended up mandating that bug (mandating that system("+c")
> should run an interactive shell for instance), because, like the
> the Unix libc implementors, they overlooked the issue. It is
> clearly a bug in the standard.
It doesn't mandate that system("+c") should run an interactive shell.
With dash:
$ sh -c +c
sh: 0: -c requires an argument
Ditto with bash:
$ bash -c +c
bash: -c: option requires an argument
ksh93 and mksh run an interactive shell, but I wonder whether this
should be regarded as a bug.
The sh utility has the following in SYNOPSIS:
sh −c [−abCefhimnuvx] [−o option]... [+abCefhimnuvx] [+o option]...
command_string [command_name [argument...]]
i.e. "+c" doesn't seem to be allowed to "cancel" the "-c".
Or perhaps "+c" can be seen as a command to run an interactive shell,
a bit like "sh -c sh", in which case I do not see any issue (the user
may also have a command "+c" that runs sh in his path, in which case
adding "--" would not change the ksh behavior).
--
Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
