mgnokiidev is a tool from the gnokii tool suite used to create the link /dev/gnokii that points to a pseudo-tty (/dev/pts/?).
It is called after gnokiid has created a virtual modem that is attached to the pty. It's operation is transparent under normal usage as gnokiid takes care of calling it when required.
Since mgnokiidev must modifiy files in /dev, it must be either run as root or SUID root. The latter is the preferred method. Normally the mgnokiidev binary is chmod 4750 and owned by root.gnokii.
gnokii is a Linux/Unix tool suite and (eventually) modem/fax driver for Nokia mobile phones, released under the GPL.
gnokii supports most phones from the 3810/8110 and 5110/6110 series, details including bugs specific to each series appear in the files Docs/README-3810 and Docs/README-6110 respectively.
This manual page was written by Erik Rossen <firstname.lastname@example.org>.
See also Docs/CREDITS from the gnokii sources.