#!/bin/sh

# 设置要检测的设备名和挂载点
DEVICE_NAME="/dev/sdb1"
MOUNT_POINT="/usb_disk"

#判断是否已经挂载
isMounted() {
    mount_output=$(mount)
    if [[ "$mount_output" == *"$1"* ]]; then
        return 0
    else
        return 1
    fi
}

#判断设备文件是否存在
file_exists() {
    if [ -e "$1" ]; then
        return 0
    else
        return 1
    fi
}

out_log(){
    echo "$@"
    logger  "easy auto mount:" "$@"
    return 0
}

#mount -t ntfs-3g /dev/sdb1 /usb_disk

run_cmd() {
    out_log "$@"
    command "$@"
    return $?
}

#执行次数
run_count=0

#如果发生错误,最多重试15次.
while [ $run_count -le 15 ]; do
    
    #if [ $run_count -gt 0 ]; then
        #每次延时1秒
        sleep 1
    #fi

    run_count=$((run_count + 1))

    if file_exists $DEVICE_NAME; then
        #设备存在
        out_log "设备:"$DEVICE_NAME "已接入."

        if ! isMounted $MOUNT_POINT; then
            #没有挂载.

            #如果是挂载到别的地方去了,需要卸载.
            if isMounted $DEVICE_NAME; then

                out_log "这个设备挂载到别处了,需要卸载..."
                if ! run_cmd umount $DEVICE_NAME; then
                    continue
                fi
            fi
            
            if ! file_exists $MOUNT_POINT; then
                out_log "创建挂载点文件夹:"$MOUNT_POINT

                if ! run_cmd mkdir $MOUNT_POINT; then
                    continue
                fi
            fi

            out_log "开始挂载..."
            
            if ! run_cmd mount -t ntfs-3g $DEVICE_NAME $MOUNT_POINT; then
                continue
            fi
            
            out_log "挂载成功!"
        else

            out_log "设备:"$DEVICE_NAME",已正常挂载为:"$MOUNT_POINT ",不需要操作"

            #已经挂载了.
            #out_log "开始卸载..."
            #if ! run_cmd umount $MOUNT_POINT; then
                #continue
            #fi
        fi


    else
        out_log "设备不存在"
    fi

    exit 0
done

out_log "操作失败,执行超时!"