Most of the unix-commands on the MyBook are applets from the multi-call binary "busybox" (the swiss-army-knife for embedded unix). Playing around with other small unix-machines like Fonera or the german Oyo-ebook-reader i saw that some basic and very helpful commands are not available from the installed busybox.
As a short description: all the commands are compiled within one big binary and are called over links. You can see it by exploring the /bin or /usr/bin-directory, for example the command "vi" is also a symbolic link to /bin/busybox. By executing busybox without a parameter it gives you all the includes applets (about 200?) but some commands (for example "basename" or "wc") are missing.
The last stable busybox-binary has 348 applets inside so i installed the full-featured version next to the default.
You can get it here:
I renamed the file to "busybox_new", copied it to /bin and chmod 755. Then make links for your desired programs, for example " ln -s /bin/busybox_new /bin/wc " to have the wc-utility (word-count) directly working.
All applets can be accessed also by calling them on the command-line as a parameter, for example "./bin/busybox_new wc" on the prompt also works.
The command "/bin/busybox_new —list" shows a complete listing of the applets, look what you need and create your links :-)
But be careful: do not replace the installed version, making additional links to the missing commands is more secure i think and take care not to link the same tool twice!
AND: there is a kind of caching of commands, if you replace already linked commands the old one is used until you reboot your mybook.