ls -l on Android device

[Denys Vlasenko]

On Sunday 24 January 2010 11:46, Tom Spear wrote:
> On Wed, Jan 13, 2010 at 12:15 AM, Tom Spear <speeddymon at gmail.com> wrote:
> > Ok. I'll try it this weekend. I don't think I'll have time before then
> > unfortunately. :-(
> 
> I was finally able to get this done. I had to comment the pw_gecos
> call to get it to compile:
> 
> [tom at Speeddy testapp]$ agcc -o test test.c
> test.c: In function 'dump':
> test.c:15: error: 'struct passwd' has no member named 'pw_gecos'
> 
> But once I did that, it compiled fine, output is below:
> 
> [tom at Speeddy testapp]$ adb shell
> # /system/bin/test 2000 shell
> pw_name:shell
> pw_passwd:(null)
> pw_uid:2000
> pw_gid:2000
> pw_dir:/
> pw_shell:/system/bin/sh
> 
> pw_name:shell
> pw_passwd:(null)
> pw_uid:2000
> pw_gid:2000
> pw_dir:/
> pw_shell:/system/bin/sh
> 
> # /system/bin/test 0 root
> pw_name:root
> pw_passwd:(null)
> pw_uid:0
> pw_gid:0
> pw_dir:/
> pw_shell:/system/bin/sh
> 
> pw_name:root
> pw_passwd:(null)
> pw_uid:0
> pw_gid:0
> pw_dir:/
> pw_shell:/system/bin/sh
> 
> 
> It looks like it all works fine, so I am unsure why the calls don't
> return the name associated with the uid/gid.

Ok. Let's dig deeper. Earlier you said that busibox id gives this:

$ ./busybox id
uid=2000 gid=2000 groups=1003,1004,1007,1011,1015,3001,3002,3003

Looking at the source, "id" with no parameters ends up here
in id.c:

static int print_group(gid_t id, const char *prefix)
{
        return print_common(id, gid2group(id), prefix);
}

static int print_user(uid_t id, const char *prefix)
{
        return print_common(id, uid2uname(id), prefix);
}

Let's follow uid2uname: it's in libbb/bb_pwd.c:

char* FAST_FUNC uid2uname(uid_t uid)
{
        struct passwd *pw = getpwuid(uid);
        return (pw) ? pw->pw_name : NULL;
}

As you see, it uses the very same getpwuid() call.
Please instrument it by adding this line:

        struct passwd *pw = getpwuid(uid);
bb_error_msg("getpwuid(%d):%p", (int)uid, pw);
        return (pw) ? pw->pw_name : NULL;

recompile bucubox, making sure CONFIG_USE_BB_PWD_GRP
and CONFIG_USE_BB_SHADOW are off, then re-run
"./busybox id". What does it print? Give the same uid to
"/system/bin/test <UID> root" - does it resolve it?
--
vda