Very Computer

by **marc** » Thu, 30 Jul 1998 04:00:00

Is there a C function which returns the user-name for the user id?

Thanks, Marc

by **Andrew Giert** » Thu, 30 Jul 1998 04:00:00

marc> Is there a C function which returns the user-name for the user id?

getpwuid()

--
Andrew.

comp.unix.programmer FAQ: see <URL: http://www.erlenstar.demon.co.uk/unix/>
or <URL: http://www.whitefang.com/unix/>

by **mattr..** » Thu, 30 Jul 1998 04:00:00

>Is there a C function which returns the user-name for the user id?

>Thanks, Marc

There should be a function like getpwnam() or something like that
where you give the user id and it returns the user name.

Someone is borrowing my UNIX programming book so I can't tell you for
sure, but I do believe it exists.
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Matt

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- These views are my own, not necessarily those of my company.

by **Marc Dzaebe** » Thu, 30 Jul 1998 04:00:00

> marc> Is there a C function which returns the user-name for the user id?

> getpwuid()

> --
> Andrew.

Hi Andrew, (hi Mattryan)

Ok, getpwuid(uid)->pw_name returns the /etc/passwd user and the
shadow password can also be determined by getspnam but what if you
are connected to NIS/YP-Server or other name services? Is there
a portable way to get the user-name on HP-UX, Solaris, Linux?
E.g. on HP-UX / SCO you need to use different commands (FAQ).
May be I should look in the 'id' command, but I don't have the
sources. However, I hope that your mentioned method works
for most cases. What Unix book would you recommend here?

Thanks a lot for you perfect help!

Yours, Marc Dzaebel

by **mattr..** » Thu, 30 Jul 1998 04:00:00

>> marc> Is there a C function which returns the user-name for the user id?

>> getpwuid()

>> --
>> Andrew.

>Hi Andrew, (hi Mattryan)

>Ok, getpwuid(uid)->pw_name returns the /etc/passwd user and the
>shadow password can also be determined by getspnam but what if you
>are connected to NIS/YP-Server or other name services? Is there
>a portable way to get the user-name on HP-UX, Solaris, Linux?
>E.g. on HP-UX / SCO you need to use different commands (FAQ).
>May be I should look in the 'id' command, but I don't have the
>sources. However, I hope that your mentioned method works
>for most cases. What Unix book would you recommend here?

>Thanks a lot for you perfect help!

>Yours, Marc Dzaebel

Advanced Programming in the UNIX Environment by W. Richard Stevens is
highly recommended, at least by me.
------
Remove "nospam" to respond via email.

Matt

------
- These views are my own, not necessarily those of my company.

by **Adel Abushae** » Fri, 31 Jul 1998 04:00:00

> Is there a C function which returns the user-name for the user id?

man getpwuid(), probably it will help you.

Adel.

Quote:> Thanks, Marc

by **Marc Dzaebe** » Sun, 02 Aug 1998 04:00:00

> > Ok, getpwuid(uid)->pw_name returns the /etc/passwd user and the
> > shadow password can also be determined by getspnam but what if you
> > are connected to NIS/YP-Server or other name services? Is there
> > a portable way to get the user-name on HP-UX, Solaris, Linux?

> I can't say for all the flavors you mention, but getpwuid() on Solaris
> will automatically use NIS if /etc/nsswitch.conf is properly set.

> ron
> ----------------------------------------------------------------------
> Ron Klatchko - Senior Software Engineer
> UCSF Library and Center for Knowledge Management

Yes, many confirmed this but I experienced that the call is
dramatically slow (1/10 sec). So I would always recommend to cache uids
and user-names.

Thanks for your answer,

Marc Dzaebel

Very Computer

user id -> user name?

user id -> user name?

user id -> user name?

user id -> user name?

user id -> user name?

user id -> user name?

user id -> user name?

user id -> user name?