Common Linux commands and common linux commands

Common Linux commands and common linux commands

• R read 4

• W write 2

• X excute execution 1

• -No permission 0

• Each 3 is a group. The permission is 4 + 2 + 1 4 + 1 4 + 1, that is, 7 5 5.

• Df view disk storage and usage information

  • The/dev/sda1 disk partition in the first column is equivalent to the C disk in Windows.

  • The Mounted on in the last column is equivalent to a Windows drive letter.

Top view system processes and CPU usage

• Cpu (s): 1.0% us 18.4% sy, 0.0% ni, 0.0% id, 63.5% wa, 0.0% hi, 7.2% si

  • Us represents the user, indicating the CPU usage occupied by normal users.

  • Sy stands for system, and the CPU occupied by the operating system itself

  • Wa stands for iowait, 63.5% wa, and represents the I/O operation of the hard disk or network port, waiting for the I/O time ratio

  • Idle: cpu idle rate

• Mem: 1004772 k total, 933184 k used, 71588 k free, 215624 k buffers

  • Mem, indicating memory

  • Total: total memory

  • Used: memory usage

  • Free: Memory idle

  • Buffers, buffer zone

• Swap: 786428 k total, 13784 k used, 772644 k free, 58350 k cached

  • Cached, indicating cache, pre-occupied memory, actually not used so much, but will directly get the memory from these memories

  • The real memory idle rate is Mem free + buffers + cached.

• Pid, which is the process number

• Q or ctrl + c can exit the top Command