I need to create a new user account on Sun box. How to use a shell
script to find out the lowest and available uid and gid for this new
user?

Thanks!

[ Post a follow-up to this message ]

In article <1169052333.308114.242390@s34g2000cwa.googlegroups.com>,
<goodshi@gmail.com> wrote:
>I need to create a new user account on Sun box. How to use a shell
>script to find out the lowest <deleted: and> available uid and gid
>for this new user?

Here's a function I wrote some time back for precisely that purpose:

# Usage: uid=`getuid 380`       find the lowest available ID >= 380

getuid() {
sort -t: +2n -3 /etc/passwd |
nawk -F: -v val=$1 '$3 == val {val++} END {print val}'
}

You could probably do it all (i.e. w/o the external "sort") in GAWK or some
other modern AWK that has built-in sorting capability.

[ Post a follow-up to this message ]

In article <1169052333.308114.242390@s34g2000cwa.googlegroups.com>,
<goodshi@gmail.com> wrote:
>I need to create a new user account on Sun box. How to use a shell
>script to find out the lowest and available uid and gid for this new
>user?

Assuming you have the system configured in such a way that all of the UIDs a
re
actually stored in /etc/passwd:

awk -F: '{ j[$3] } END { for (i = 200; i in j; i++); print i }
' /etc/passwd

Replace 200 with the lowest uid you want to use.
Modify in the obvious way for gid.

John
--
John DuBois  spcecdt@armory.com  KC6QKZ/AE  http://www.armory.com/~spcecdt/

[ Post a follow-up to this message ]

Thanks, John,
One thing was missing. We are using NIS. So some UIDs are not in local
/etc/passwd file.

John DuBois wrote:[vbcol=seagreen]
> In article <1169052333.308114.242390@s34g2000cwa.googlegroups.com>,
>  <goodshi@gmail.com> wrote: 
>
> Assuming you have the system configured in such a way that all of the UIDs
 are
> actually stored in /etc/passwd:
>
> awk -F: '{ j[$3] } END { for (i = 200; i in j; i++); print i
 }' /etc/passwd
>
> Replace 200 with the lowest uid you want to use.
> Modify in the obvious way for gid.
>
> 	John
> --
> John DuBois  spcecdt@armory.com  KC6QKZ/AE  http://www.armory.com/~spcecdt/[/vbcol
]

[ Post a follow-up to this message ]

2007-01-17, 08:45(-08), goodshi@gmail.com:
> I need to create a new user account on Sun box. How to use a shell
> script to find out the lowest and available uid and gid for this new
> user?

min=1000
{
cat /etc/passwd
ypcat passwd
getent passwd
} 2> /dev/null | cut -d: -f3 | sort -un |
awk -v "min=$min" '
$0 > min {exit}
$0 == min {min=$0+1}
END {print min}'


--
Stéphane

[ Post a follow-up to this message ]

2007-01-17, 21:17(+00), Stephane CHAZELAS:
> 2007-01-17, 08:45(-08), goodshi@gmail.com: 
>
> min=1000
> {
>   cat /etc/passwd
>   ypcat passwd
>   getent passwd
> } 2> /dev/null | cut -d: -f3 | sort -un |
>   awk -v "min=$min" '
>     $0 > min {exit}
>     $0 == min {min=$0+1}
>     END {print min}'

Though you may want to check that the value is supported by your
OS:

min=1000 max=65535
{
cat /etc/passwd
ypcat passwd
getent passwd
} 2> /dev/null |
cut -d: -f3 |
sort -un |
awk -v "min=$min" -v "max=$max" '
$0 > min {exit}
$0 == min {min++}
END {
if (min > max)
exit(1)
print min
}'

--
Stéphane

[ Post a follow-up to this message ]

Kenny McCormack wrote:
> In article <1169052333.308114.242390@s34g2000cwa.googlegroups.com>,
>  <goodshi@gmail.com> wrote: 
> getuid() { ... }

This and subsequent solutions do not address the circumstance
of "holes" in used UIDs and GIDs, as per the OP's request.

The algorithm for finding the first _available_ UID/GID is to sort
the list (as above), and determine the number which is not one
greater than the previous UID/GID. The first available UID/GID is
the previous number plus one. If there is no such number,
_then_ the first available UID/GID is the last number plus one.

=Brian

[ Post a follow-up to this message ]

2007-01-17, 15:07(-08), bsh:
>
> Kenny McCormack wrote: 
>
> This and subsequent solutions do not address the circumstance
> of "holes" in used UIDs and GIDs, as per the OP's request.
>
> The algorithm for finding the first _available_ UID/GID is to sort
> the list (as above), and determine the number which is not one
> greater than the previous UID/GID. The first available UID/GID is
> the previous number plus one. If there is no such number,
> _then_ the first available UID/GID is the last number plus one.
[...]

I'd suggest you reread the provided solution. All do what you
say using a more or less cleaver algorithm.


--
Stéphane

[ Post a follow-up to this message ]

Stephane CHAZELAS wrote:
> bsh wrote: 
> I'd suggest you reread the provided solution. All do what you
> say using a more or less cleaver algorithm.

To look at it again, then: Darn it! You're right.

I can then only add a suggestion to avoid using sort(1)
and awk(1) for such a simple task, and instead use
"set -s -- ..." and a "for" loop to iterate through the
numbers.

=Brian

[ Post a follow-up to this message ]

2007-01-18, 14:16(-08), bsh:
>
> Stephane CHAZELAS wrote: 
>
> To look at it again, then: Darn it! You're right.
>
> I can then only add a suggestion to avoid using sort(1)
> and awk(1) for such a simple task, and instead use
> "set -s -- ..." and a "for" loop to iterate through the
> numbers.
[...]

Why?

And I'm afraid set -s is ksh/zsh specific.

--
Stéphane

[ Post a follow-up to this message ]