Linux

1 DMA ConceptsDMA as the name implies refers to the device and memory, memory and external storage devices for direct data read and write operations, without the need for CPU participation. 2 DMA PrincipleDMA transfer needs to be performed by DMA

SUID to set User IDSGID is set Group ID SUID When an executable with a suid bit is executed, the file will run as the owner, meaning that whoever executes the file has the file owner's privileges. If the owner is root, then the executor has the

Always want to learn Linux, and do not know where to start, read a lot of books, are also looking at the total feeling yangaoshoudi, see what all déjà vu, do not find the north. Determined to look from the code, the latest code is too long,

It's been a long day and it's finally done. Ubuntu does not have root permissions, just started with a lot of trouble, check a lot of information, finally Arm-linux-gcc:command not found problem solved. Problem: sudo tar jxvfcross-2.95.3

A simple implementation method of Linux detecting TCP connection disconnection Generally can take the business layer of heartbeat detection, timeout did not receive a heartbeat packet, it is considered to end has been disconnected, but

1. The first operand is source and the second is destination (just the opposite of Intel). Copy the contents of the EAX register to EBX: MOVL %eax,%EBX 2. Register before the name to add% 3. Add $ immediately before the number. Static

Uninstall 1, uninstall the installed JDK method with bin file: Delete Everything under the/usr/java directory 2, uninstall the system's own JDK version method: View the JDK: #rpm-qa | grep GCJ See the following information: Libgcj-4.1.2-44.el5 java-1

Introduction "Oops, the system hangs dead ..." "Oops, the program crashes ..." "Oops, command to perform an error ..." For the maintenance staff, such tragedies are being staged every day. Ideally, the system or application error log provides

For a file, there is a unique index point corresponding to it, and for an index contact number, but can have more than one file name corresponding to it. Therefore, the same file on disk can access the file through a different path.1. The connection

Embedded Linux Learning Seven Steps Sailor_forever sailing_9806@163.com Reprint Please specify Http://blog.csdn.net/sailor_8318/archive/2007/09/03/1769662.aspx "Thank you for your attention" Seven steps of all ppt in this, Word version is still in

http://blog.csdn.net/zs634134578/article/details/20475741 Problem Focus: Processes are the foundation of the Linux operating system environment. This article discusses the following elements, but also the interview is often asked some questions: 1

In the development environment, we can use Samba to map the cost of the network drive, directly in the Windows environment for programming debugging. But the final release is going to the Linux environment, and we have the Web server and database

We can usually use iptables to set up some firewall rules in Linux systems. Iptables-t nat-a output-p tcp-j REDIRECT * * * * * * * * * application, the rule is only saved in memory, and the next time it restarts, the/etc/sysconfig/iptables firewall

Linux has the following 4 main commands related to lookup: Whereis, locate, find, which. Find is not commonly used, whereis and locate often used, because Whereis and locate is to use the database to find data, and found directly look for hard disk,

Original address : http://www.cnblogs.com/younes/archive/2010/01/19/1651746.html author : Unity of knowledge and line [1] When you see the boot menu: Select the kernel kernel (recovery mode) to start and press E. into a new interface. [2] Move the

1. Set the environment variable directive: Export For example: Export m2_home= "/opt/maven" This instruction set the M2_home point to a path Echo View echo $M 2_home If m2_home is defined, its value is displayed Modify Modify the environment

using awk for advanced text processingAwk is a tool designed for data flow. It's quite popular because you can manipulate columns and rows. AWK has many built-in functions, such as arrays, functions, and so on, which is the same as the C language.

rps/rfs principle in Linux kernel network In the last chapter, explained the network soft interrupt's mechanism and the optimization in the whole, but in the RPS and the RFS place did not completely explain clearly, only has described its overall

CP Copy files or directories Grammar CP [option] source file destination file Common options: -A: equivalent to PDR -D: Copies the linked file, which is also a linked file or directory that points to the source file link. -I: When the

If you use a dynamically-linked library. So file that you manually generated, but this. So file is not added to the library search road, the program may run with a situation where the dynamic link library cannot be found. You can view the