INSTALL

Tested on:
Mac OS X, RedHat , Debian, FreeBSD  ( required to run snmp as root )

Prerequisites:

net-snmp server
net-snmp-perl modules

in the order the included sample to work you also need /usr/sbin/ntpdate utility.

Installation:

Standard to GNU. 
aclocal
automake --add-missing
autoconf
configure --prefix=/usr --sysconfdir=/etc # if you choose another directories, you have to amend path appropriately below
make install DESTDIR=<target directory>

3. run subagent-shell:
way 1:
add th line to snmpd.conf:
perl do "/etc/snmp/subagent/subagent-shell";

way 2(recommended):
copy subagent-shell.init to /etc/init.d/subagent-shell (Sys V scripts directory)
copy subagent-shell to /usr/bin

start subagent-shell:
/etc/init.d/subagent-shell start

4. optional. read and amend subagent-shell-functions-conf.xml  

5. restart snmpd server

Verification:

snmpwalk  -v2c  -M+/etc/snmp/subagent/mibs -mALL -c public localhost SUBAGENT-SHELL   | head -9
SUBAGENT-SHELL-MIB::ssFunctionsCount = INTEGER: 6
SUBAGENT-SHELL-MIB::ssFunctionsSuccessCount = INTEGER: 6
SUBAGENT-SHELL-MIB::ssFunctionsFailedCount = INTEGER: 0
SUBAGENT-SHELL-MIB::ssTimeStamp = STRING: "09-Sep-2013 17:38:59 (1378733939)"
SUBAGENT-SHELL-MIB::ssTotalExecTime = STRING: "0.365"
SUBAGENT-SHELL-NTP-SYNCSTATUS-MIB::ntpSyncStatus = STRING: "-0.001"
SUBAGENT-SHELL-NTP-SYNCSTATUS-MIB::ntpSyncServer = STRING: "ntp"
SUBAGENT-SHELL-NTP-SYNCSTATUS-MIB::ntpSyncFuncExecTime = STRING: "0.321"
SUBAGENT-SHELL-NTP-SYNCSTATUS-MIB::ntpSyncExecStatus = INTEGER: 0


Troubleshuting:
Check system log for errors
Read the source :)