Dynamic duty drawback calculations

List of contents of this article:

• 1,< A href='#linux check the current time' title='linux check whenTime before'>linux Check the current time
• 2, linux how to use the top command to view the system status
• 3、linux system hardware time and system time

linux view current time

1. System time: generally speaking, we execute d The time seen by the ate command, all time calls under the Linux system (except for the command to directly access the hardware time) are used at this time.

2. Does the questioner want to ask "What is the command of linux to check the current time"? Date. According to the query of Zhongguancun Online, the command to view the current time in the Linux system is date. You only need to open the system and enter it in the command bar.

3. Can passCheck the status of the file through the stat command, where accesstime: read the content of the file once, and the time will be updated. For example, use the less command or more command for this file.

4. Use the date command to check the current time of the system. Use "date-s hour minutes and seconds" to modify the system time. Use the command: "date-s complete date and time (YYYY-MM-DDhh: mm)" to modify the date and time of the Linux system. Finally, use the command: "hwclock-w" to write the time to bios to avoid restart failure.

5. Display time: year/month/day. -d parameter, indicating that what is to be displayed is the time represented by the following string, 1 day ago indicates the time 1 day ago.Date +%Y-%m-%d %H-%M-%S This is the display time + and then the time format.

6. The time inside of Linux is timestemp. This time output is based on the settings of the current time zone. The setting file of the current time zone is /etc/localtime (if I remember correctly). Even if you don't set the time zone, the system will still have a default time zone for output.

linux how to use the top command to view the system status

t Op is a dynamic display process, that is, the current state can be constantly refreshed through the user button. If the command is executed in the foreground, it will exclusively display the CPU, memory usage and execution time in the foreground until the program is terminated by pressing ctrl+C.

m: switch to display memory information; t: switch to display process and CPU status information; c: switch to display command name and complete command line; M: sort according to resident memory size; P: sort according to CPU usage percentage size;T: Sort according to time/cumulative time; w: Write the current settings to the ~/.toprc file.

Line 4: Total amount of physical memory, usage, idle amount, as the amount of memory cached by the kernel. Line 5: Total amount of virtual memory, usage, idle amount, memory data that has been loaded in advance.

The top command can dynamically display the resource occupation status of Linux. The top command commonly uses the -d option. The -d option indicates the number of seconds the interface update of the top command (the default is updated once every 5 seconds). Generally, the -d option is set to 2, which means that it is updated once every 2 seconds.

Linux system can view the system's CPU, memory, runtime, swap partition, executed threads and other information through the top command.Through the top command, you can effectively find out where the system's defects are. It is because the memory is insufficient, the CPU processing capacity is insufficient, and the IO reading and writing are too high.

top command The top command is used to dynamically monitor information such as process activity and system load, and its format is top. The top command is quite powerful and can dynamically view the status of system operation and maintenance, and completely regarded it as an "enhanced version of Windows Task Manager" in Linux. The running interface of the top command is shown in the figure.

linux system hardware time and system time

linux system contains two kinds of time, one is system time and the other is hardware time.

GuideThe reason for this is that Winows and Linux handle hardware time differently. Windows treats hardware time as local time, while Linux treats hardware time as UTC time. Therefore, there will be an eight-hour difference between using Windows and Linux in China's UTC+8 time zone.

According to the previous statement, when restarting the system, the hardware time will read the system time to achieve synchronization, but when it is not restarted, it needs to be synchronized with the hwclock command.

The time we generally see is the system time, and the hardware time refers to the CMOS time on the motherboard. These two times are not always synchronized, and generally every 11 minutes.When the system starts, the time will be read from the CMOS as the system time, and then the system time is independent.