1. The command line is more bandwidth-saving than the graphical interfaceThe 2.linux file size is indicated by default in bytes, 1kb=1024 bytes, 1 bytes 8 bits (1byte=8bit)3.linux Multi-line Comment:: <<!AAABBBCCC!4.MV moving files to the directory: mv Aa.txt bb/ to move the AA text to the BB directory mkdir-p aa/bb/cc/dd/ee Creating a directory recursively5.tree View Catalog6.32bit System, hardware front-end bus and CPU bits are 32 bits, can support the largest memory address 4GB7.man View Helpcommand--help simple helpHelp commands (such as CDs) to view some of the built-in commands for the Linux command line8.grep-n file content filename finds matches in the file and the number of rows that appear9.DU View specified file size10.chmod modifying file PermissionsChown Modifying a group of files11.top command to view system health status,CPU Focus: User (the CPU occupied by the users process)System (CPU of operating system capability)Idle (CPU idle rate)iowait (CPU waits time ratio of IO)12. Operating system memory Usage common sense:system uses memory =Total-free app uses memory =total-(free+cached+buffers) caches and buffers are only used to read files for the operating system.feature Read PolicyCache cache is used primarily for open file least use principle (LRU)Buffer sub-cache is mainly used for directory items, inode and other file system FIFO strategywhen cache usage is large, the file reads frequently
Linux Little Common Sense
