Linux

1. Modify the/etc/profile fileThis method is recommended if your computer is used only for development, because all users' shells have the right to use these environment variables, which may bring security issues to the system. (1)

C # provides reflection that makes it easy for us to dynamically load a specified DLL at runtime and call its classes and methods. Reasonable Use of this feature can greatly improve ProgramFlexibility. C/C ++ development in Linux certainly cannot

/** MyCat. c ** copyright 2013 spark **/# include int main (INT argc, char ** argv) {file * FP; void filecopy (File *, file *); If (argc = 1) {filecopy (stdin, stdout);} else {While (-- argc> 0) {If (FP = fopen (* ++ argv, "R") = NULL) {printf

Permission: All Users Usage: chmod [-CFVR] [-- help] [-- version] mode file... Note: file access permissions for Linux/Unix are classified into three levels: file owner, group, and others. Chmod can be used to control how files are accessed by

Linux Note 1 1. append standard output to the file Use the append output symbol> to add new content to the end of a file.For example:$ Cat orangeThis is an orange.$ Cat pear> orange$ Cat orangeThis is an orange.This is an pear. 2. Redirect

When the disk size exceeds the standard, an alarm is triggered. it is wise to master the DF and Du commands. DF allows you to view the size, usage ratio, file system, and its mount point of a level-1 folder, but there is nothing to do with files.Du

After Linux is installed, there will be a root user. So how can I change the root user password without knowing the password? In this system, the RedHat Linux installation environment is VMware 6.0 guided by grub. The method is as follows: 1.

Review:1. QT CompilationQmake*. Pro File Format2. QT toolsHelp documentationConfiguration toolsUidesigner3. Use of QT classes I. Signal and slot1. Background:Process-orientedLow coupling design between modules (High Cohesion ).Function call:Direct

BRK/sbrk maintains a location. BRK/sbrk changes this position. BRK changes absolute position sbrk changes relative position yesterday's supplement: always remember: There are several basic types of C. All new types are redefined using typedef.

1. Calculate the system memory occupied by Apache PS aux |GrepApache | awk '{sum + = $4}; End {PrintSum }' Note: $4 indicates the fourth domain 2. Tips in VIM (For the current screen) H-jump to the first line m-jump to the middle line L-jump

Introduction to multiple tasks in Linux First, let's briefly introduce what is a multitasking system? What are the tasks, processes, and threads? What is the difference between them ?, In this way, you can take a macro look at the three, and then

( 2 ) separation and integration of threads at any point in time, threads can be combined ( joinable ), or separated ( detached ). A combined thread can be reclaimed and killed by other threads ; before being recycled by other

When I use Linux, I have a habit of putting some useful and easy-to-Forget commands into a text file. If it's okay, I can take a look, in this way, the image can be deepened, and the usage of these commands can be basically mastered for a long time.

Netlink is a special socket, which is unique in Linux. It is similar to af_route in BSD but far more powerful than Netlink. Currently, Netlink is in the latest Linux kernel (2.6.14) there are many applications that use Netlink to communicate with

Tar -C: Create a compressed file-X: Extract-T: View content-R: append an object to the end of the compressed archive object-U: update files in the original compressed package These five are independent commands, one of which must be used for

Is there any function similar to fork in windows? Fork can copy all process information from the current process to another process, and then the two processes can execute differentCode. Windows does not have fork. Only CreateProcess is available,

Since we have previously written multi-process statements, but because resources need to be shared (that is, some variables are shared), although the process can share resources through other methods, it is better to use threads! So I changed it

IntroductionSwitch between the Linux console and the graphic interfaceFamiliar with Linux commandsThis section describes commands that are frequently used.File Operation commandsDirectory commandFile comparison commandAdd User and change PASSWORD

1. Insert a USB flash drive2. Input fdisk-L/dev/SDA to view the output result. For example, mine is like this:# Fdisk-L/dev/SDADisk/dev/SDA: 131 MB, 131104768 bytes3 heads, 32 sectors/track, 2667 CylindersUnits = cylinders of 96*512 = 49152

1. The Recv and send functions provide functions similar to read and write. However, they provide the fourth parameter to control read/write operations. Int Recv (INT sockfd, void * Buf, int Len, int flags) Int send (INT sockfd, void * Buf, int Len,