tar and gzip
tar -cf target.tar file1 file2 #add file1 file2 into target.tar
tar -czvf abc.tar.gz abc.tar #add and zip abc.tar into abc.tar.gz
-c create
-z compress
-v show the progress
-f specify the file name
tar -xzvf abc.tar.gz
PSCP
pscp (windows to linux home folder)
pscp.exe your_file user@192.168.1.1:yourfile
pscp (linux home folder to windows)
pscp.exe user@192.168.1.1:yourfile your_file_in_win
if the linux server is at a different port (other than 22), use -P to sepecify the port number
show processes
sudo ps -aux
kill a process gracefully, but sometimes it may not respond
sudo kill 'pid'
kill a process brutally. the -9 is a magic
sudo kill -9 'pid'