Command Format: ACKNOWLEDGE_HOST_PROBLEM;<host_name>;<sticky>;<notify>;<persistent>;<author>;<comment>

Description: Allows you to acknowledge the current problem for the specified host. By acknowledging the current problem, future notifications (for the same host state) are disabled. If the “sticky” option is set to two (2), the acknowledgement will remain until the host returns to an UP state. Otherwise the acknowledgement will automatically be removed when the host changes state. If the “notify” option is set to one (1), a notification will be sent out to contacts indicating that the current host problem has been acknowledged. If the “persistent” option is set to one (1), the comment associated with the acknowledgement will survive across restarts of the Nagios process. If not, the comment will be deleted the next time Nagios restarts.

#!/bin/sh
# This is a sample shell script showing how you can submit the ACKNOWLEDGE_HOST_PROBLEM command
# to Nagios.  Adjust variables to fit your environment as necessary.
 
now=`date +%s`
commandfile='/usr/local/nagios/var/rw/nagios.cmd'
 
/bin/printf "[%lu] ACKNOWLEDGE_HOST_PROBLEM;host1;2;1;1;Some One;Some Acknowledgement Comment\n" $now > $commandfile

https://old.nagios.org/developerinfo/externalcommands/commandlist.php