Command to get system hardware serial number.

SMBIOS/DMI standard includes system manufacturer, model name, serial number, BIOS version, asset tag as well as a lot of other details of varying level of interest and reliability depending on the manufacturer. This will often include usage status for the CPU sockets, expansion slots (e.g. AGP, PCI, ISA) and memory module slots, and the list of I/O ports (e.g. serial, parallel, USB).
Solaris X86:

$smbios
  ..
  Manufacturer: HP
  Product: ProLiant DL360 G3
  Serial Number: B038XXXXX
  ..

Solaris Sparc:
smbios is not supported in SPARC yet, the traditional command prtdiag works for both X86 and SPARC ,but it reports less detailed hardware information.

Linux/BSD:

$dmidecode

Create restricted login account

Create a login in restricted shell and doesn’t allow user to change password.

rsh is a limiting version of the standard command inter-
preter sh, used to restrict logins to execution environments
whose capabilities are more controlled than those of sh (see
sh(1) for complete description and usage).

The actions of rsh are identical to those of sh, except that
the following are disallowed:

changing directory (see cd(1)),

setting the value of $PATH,

pecifying path or command names containing /,

redirecting output (> and >>).

Set restricted shell as login shell

Solaris:
usermod  -s /usr/lib/rsh userid
Linux:
usermod  -s /usr/bin/rbash userid

Set minimum number of days between password changes to large number, so user can’t change password until min days

Solaris:
passwd  -n 9999 –x 9998 userid
(Solaris needs to set both Min Max days and Min is greater than Max)
Linux:
passwd –n 9999 userid