By default, the command line history is stored as long as you don't reboot or power off your router. However, It's possible to make it persistent by using permanent storage, such as JFFS or USB attached storage.
The command history is kept in: “/tmp/home/root/.ash_history” .
We can use FreshTomato's ability to execute a script at boot and at shutdown to backup and restore the command history to make it persistent across reboots. To do so, we need 2 scripts. One script will execute on shutdown to backup the history to permanent storage. The other will restore the history on boot.
This shutdown script will save the last 100 used commands. If you want to retain more, change '100' to whatever number you wish. Name your backup script “cli_history_save.autostop” and use the following code:
#!/bin/sh tail -n 100 /tmp/home/root/.ash_history > ${1}/.ash_history
This second script will restore the command history when booting.
Name your restore script “cli_history_restore.autorun”:
#!/bin/sh cp -f ${1}/.ash_history /tmp/home/root/.ash_history
Make sure to place the scripts in the storage mount directory, for example: “/jffs” for JFFS or “/tmp/mnt/sda1” for USB.
(Replace “sda1” with the name of your actual partition). Then, make the scripts executable with chmod:
chmod +x cli_history_save.autostop cli_history_restore.autorun