The query always checks the flag bit. Is it set to 1? If so, read or interrupt with other operations, that is, don't worry about it at ordinary times. Once something comes, it will enter the interrupt service program. When you operate DMA, write down the serial address and the address to be transmitted during initialization, and he will save the data to your initialization address.
How to deal with the network interruption of linux large file replication?
A: The network interruption mode of linux large file replication is as follows, 1. Search by file name: For example, if you forget which directory of the system this file is in, or even somewhere in the system, you can use the following command: find/
2. Error-free search skills: In the Linux system, the "find" command is a command that most system users can use, and it is not the patent of the ROOT system administrator. But ordinary users can also use the "find" command.
3. Search method based on partial file names: For example, we know that a file contains the letters srm, so we can find all files containing these letters in the system. Enter: find/ This is the solution to the network interruption of linux large file replication.
How to check the irq interrupt numbers of serial ports 3 and 4 under linux?
The first one is the /dev/ttyS0 view command setserial/dev/ttys2setserial/dev/ttys3.
What command is used to view the process under linux?
Commands that can be used by the viewing process under linux:
1, ps command to find the PID number related to the process:
2.psa displays all programs under the current terminal, including programs of other users.
3.ps-A displays all programs.
4. When psc lists programs, it displays the real instruction name of each program, but does not include the path, parameters or resident service mark.
5.ps-e The effect of this parameter is the same as that of specifying the "a" parameter.
6. When the pse lists the programs, it will display the environment variables used by each program.
7.psf displays the tree structure with ASCII characters to express the relationship between programs.
8.ps-H displays a tree structure, indicating the relationship between programs.
9.ps-N displays all programs except those under ps instruction terminal.
10, pss uses the format of program signal to display program status.
1 1, psS lists programs, including interrupted subroutine data.
12, ps-t terminal number >; Specify the terminal number and list the status of programs belonging to the terminal.
13, psu displays the plan status in a user-oriented format.
14, psx shows all programs, not terminals.
How does linux judge that the network cable is broken?
First, connect the opposite side of the network cable, such as a switch or something.
There is ethtool command in Linux to check the status of network card. For example, if the network card is eth0, then:
1
ethtooleth0
There will be a lot of output, check the line speed: if it is "unknown!" , the network cable is not connected properly, or the network card is not enabled.
Connected will display the current connection speed, for example:1000 MB/s/s.