WSL2

[Viktor Dukhovni]

On Thu, Mar 11, 2021 at 06:05:04AM -0500, Viktor Dukhovni wrote:

> So the question is why the lookup is failing.  To that end compiling a
> tracing with "strace" the below C program should tell the story:
> 
>     #include <sys/types.h>
>     #include <grp.h>
>     #include <errno.h>
>     #include <stdio.h>
> 
>     int main(int argc, char **argv)
>     {
>         struct group g, *p;
>         char buf[1024];
>         int rc;
> 
>         errno = 0;
>         rc = getgrnam_r("nosuchgrouphere", &g, buf, sizeof(buf), &p);
>         printf("%p: %m(%d)\n", p, errno);
>         return (rc == 0 && p == NULL);
>     }

To experiment with other group names and make sure that at least
group "root" or similar works, a slightly extended version is:

    #include <sys/types.h>
    #include <grp.h>
    #include <errno.h>
    #include <stdio.h>

    int main(int argc, char **argv)
    {
        char buf[1024];
        struct group g, *p;
        int rc;

        errno = 0;
        rc = getgrnam_r(argc > 1 ? argv[1] : "nosuchgrouphere",
                        &g, buf, sizeof(buf), &p);
        printf("%s(%p) %m(%d)\n", p ? g.gr_name : NULL, p, errno);
        return (rc == 0 && p == NULL);
    }

This gives (again Fedora 31) the expected results:

    $ make g
    cc     g.c   -o g
    $ ./g
    (null)((nil)) Success(0)
    $ ./g root
    root(0x7ffe6a6225d0) Success(0)

-- 
    Viktor.