ZTE c200 listen to the multicast configuration process summary records

[……]

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Little understanding of Unix System Structure

UnixLittle understanding of architecture

It can be defined as a software operating system in the strict sense,The software controls the computer hardware resources,Provider operating environment for personal understanding of hardware and software wealthy。We call such software kernel (kernel),It is relatively small,Located in the center of the environment

Kernel system call interface is called (system calls) Shared libraries built on top of the system call interface,Applications can either use the shared library,You can also use the system call。

ShellIt is a special application[……]

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Access、Trunk and Hybrid and this VLAN

Three modes switch port

On the switch,There are three commonly used configuration mode,Respectively Access (Access),Trunk (trunk or trunk) as well as Hybrid (Hybrid),These three interfaces operating mode determines the corresponding interface for processing the attitude data packets on the switch。Nowadays,Routing to elaborate on these three models。

label

Since the switch has divided the virtual LAN VLAN function is,Therefore, it is allowed to switch into the Ethernet frame data marked with a tag,VLAN is used to identify different data flows,To be forwarded。This is what we often[……]

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main (int ac, char * of[])和 main(int argc,char *argv[]) Of some of my understanding

Observance of the whereabouts of the 100th article,,,Although the content is somewhat illegible

Yesterday, see route on the main (int argc,char *argv[]) The article feels written brief said such a function

Of course first contact functions of this function is not the main (int argc,char *argv[]) But the main (int AC, char * of[])

They use the same。

Each c language program must have a function called main of[……]

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USB interface to Know

Universal Serial Bus

USB's full name is this,,In the blink of an eye,USB 1.0 standard came from the 3.0,of course,Little blue box 3.0 also does not fully into our lives,As it is now around us phone、flat、SLR,Almost still in use USB2.0 standard,Occasionally,People around him or will not tell exactly which line corresponds to which device,What can mix,Which can not。

[warning]
The line can not be mixed is not inserted into the device,Because different shapes,Can insert the,a few[……]

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c language command-line arguments argc,argv

Start

int main(int argc, const char * argv[])

In the C language learning time,We are writing a program,Then view the results in a terminal run,Enter a number, and so on ...... do not know if you have not tried it allows you to write programs that can accept parameters like system commands it? For example,:ls -al like this。

If you wish to do so,Like above, as to declare it!

among them:

argv: Pointer Pointer

argc: Integer

For chestnuts

Assumptions program[……]

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Commonly used strings in c-number function

atof(To convert a string into a floating-point number)

Related Functions atoi,atoll,strtod,strtol,strtoul
Header Files #include <stdlib.h>
Defined Functions double atof(const char * nptr);

Function Description atof()It scans the string parameter nptr,Skip over white space characters,Until a few metWord or the sign began to do the conversion,The encounter ended when non-numeric or string(‘/0’)[……]

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