Ok, I see.

2023年1月21日(土) 10:12 Andrew Pinski <pinskia@gmail.com>:

> On Fri, Jan 20, 2023 at 5:05 PM naoki ueda via Gcc-bugs
> <gcc-bugs@gcc.gnu.org> wrote:
> >
> > When I tried to execute the attached file mycalc.c with a command line
> > argument, it could not be executed normally only in the case of '*'.
> > '+', '-' and '/' can be executed normally, but the compiler cannot
> > execute '*' normally. Isn't this a gcc bug?
>
> First off this email list is really for automated messages from gcc's
> bugzilla rather than from users reporting issues.
>
> >
> >
> > ~/Clearning$ ./mycalc 20 * 30
>
> Oh * here is being handled by the shell you are using and being
> expanded as all the files in the current working directory. This has
> nothing to do with GCC really.
> You can use quotes around the * to force the shell not expanding it
> such as this:
> ./mycalc 20 '*' 30
>
> or you use \ to force the shell not to expand what comes after the * like
> this:
> ./mycalc 20 \* 30
>
> Thanks,
> Andrew Pinski
>
> > 用法:mycalc 数値1 演算子 数値2
>