usb_otg.sh

#!/system/bin/sh

mountdir=/mnt/Usb_otg

# checks number of dirs in media_rw
n=`ls -ld /mnt/media_rw/* | wc -l`

# if more than one quits
if [ $n -gt 1 ] ; then echo error: more then one mount point in /mnt/media_rw - exiting && exit 1; fi
if [ $n -lt 1 ] ; then echo error: no mount point in /mnt/media_rw - exiting && exit 1; fi

# gets the mount point of the USB OTG pendrive
mountpoint=`ls -d /mnt/media_rw/*`

# finds the device name of the pendrive
if [ -d $mountpoint ] ; then device=`mount | grep $mountpoint | cut -d' ' -f1`; fi

# check if usb_otg dir exists, if not creates it
if [ ! -d $mountdir ] ; then
    mkdir $mountdir
    chmod 777 $mountdir
fi

# unmount mount point
umount $mountpoint

if [ $? -ne 0 ] ; then
    echo error: unmouting failed - exiting
    exit 1
fi

# checks exit code and re-mounts device on new mount point.
# At last, removes the now empty old mount point
if [ $? -eq 0 ] ; then
        mount $device $mountdir
        if [ $? -ne 0 ] ; then
                echo error: mouting failed - exiting
                exit 1
        fi
        rmdir $mountpoint
fi