size of file
```
ls -l filename /* Size of the file*/
ls -l * /* Size of All the files in the current directory */
ls -al * /* Size of All the files including hidden files in the current directory */
ls -al dir/ /* Size of All the files including hidden files in the 'dir' directory */
ls -lh filename /* Size of the file in a way human can read*/
```
size of directory
```
du -sh directory_name /* Gives you the summarized(-s) size of the directory in human readable(-h) format*/
du -bsh * /* Gives you the apparent(-b) summarized(-s) size of all the files and directories in the current directory in human readable(-h
```
watch -n 1 nvidia-smi
list information of cpu
`cat /proc/cpuinfo`
1. install :
```
sudo apt-get install screen
```
2. run:
```
screen python main.py
```
3. return:
First, show all ID of session, then,return specified session by ID
```
screen -ls
screen -r id
```
4. screen的高级操作:
按照step 2启动的session一般没有名称,只有个session的id。为了更方便,可以给session起个名字
```
screen -S tarining
```
启动了一个名为**training**的session,然后会自动进入初始的bash界面。在这个界面的命令实际上就是运行在了刚才创建的session里面。
按住Ctrl,然后依次按下 a和d,可以退出当前的session,返回到主界面。