Evaluation of three mainstream Web development technologies: PHP

Why does PHP appear? It is a small application that a technician wants to use in a quick way on his personal homepage. Php appeared when he was unable to accept it. it enables a person to quickly complete a lightweight Web application under multiple operating systems. So in just a few years, php has quickly upgraded its version. Why does it happen in the GNU world? It is a small application that a technician wants to use in a quick way on his personal homepage. Php appeared when he was unable to accept it. it enables a person to quickly complete a lightweight Web application under multiple operating systems. So in just a few years, php quickly upgraded its version, and found a partner named Apache in the GNU world. This finally gives php the foundation to run in the best environment, and because both products are open-source products, so you can use their source code to combine these two products in the most perfect way, just like a product. I personally think that php is a tool for free software to win the battle on the web application platform. If php does not appear, there will also be many people who think that free software represents high technical requirements for developers, hard-to-remember code, and complex tools ..... php enables a person who uses basic to quickly learn and complete the applications required by the user in a very short time.

How does one say php? If ASP is a COM, php is more accurate. it can be said that php is a pure Script translator. This is also a major reason why php is upgraded from 3 to 4. in version 4, it overwrites the syntax analyzer, thus accelerating the overall efficiency of php. In addition, you will understand why php must re-compile the program with the lib library of the corresponding system when it needs to support this or other extended functions. Because it is an authentic "translator", it translates scripts into functions to be executed and then executes them. external expansion cannot be carried out in some "dynamic loading" ways, therefore, only static code can be compiled into php (except for windows ).

Strong:

1. a development language capable of fast learning, cross-platform, and good database interaction. ASP does not match its cross-platform capability. it is its capability that gives Unix/Linux a development language comparable to ASP. Simple syntax, easy writing, and a large number of books on the market now, while a large number of codes on the Internet can be shared, it is a good start for a beginner who wants to learn some development under "Advanced Unix.

2. work closely with Apache and other extension libraries. Php and Apache can be combined with static encoding, and can be combined with other extension libraries (except for Windows ). The biggest advantage of this method is that it maximizes the utilization of cpu time and memory, and extremely effectively utilizes apache's high-performance throughput. At the same time, external extensions are also static connections, achieving the fastest running speed. Because the interface with the database also uses this method, the local call is used, which also gives the database the best performance.

3. good security. Since php code is open, its code has been tested by many engineers. at the same time, it can be compiled with apache to provide flexible security settings. So far, php has been recognized as a secure performance.

Weak:

1. significant changes in database support. Since all the extension interfaces of php are developed by an independent team, and in order to form personalized operations on the corresponding data during development, php supports many databases, however, the development languages for each type of database are completely different. In this way, the development of a database is achieved, and almost all code changes need to be performed by developers after the database is upgraded. In order to allow applications to support more types of databases, developers need to write n types of code libraries for the same database operations, greatly increasing the workload of programmers.

2. complicated installation. Because every extension module of php is not completely completed by php itself, many external application libraries are required, and gd and LDAP are required ....... In this way, after the corresponding application is installed, it will be integrated into php. This is why I mentioned in the code Alliance News Group that php must be run in FreeBSD/Linux/Unix. Only in these environments can you easily compile the extension library corresponding to the compiler. These are common issues that developers need to face before using php. it is such a problem that many developers have switched to other development languages, so there must be fewer Unix users.

3. lack of enterprise-level support. Without the support of components, all extensions can only rely on the interfaces provided by the php development team. In fact, such interfaces are not enough. At the same time, it is difficult to add such features as clusters and application servers to the system. Such support is required for a large site or an enterprise-level application. Note: added servlet/javabean support later than php 4.0. this support may be enhanced in later versions, such support may be the starting point of enterprise-level support for php in the future.

4. lack of formal business support. This is also a shortcoming of free software. I think the number of php developers in China is growing rapidly. I believe that such support will increase in the near future.

5. commercial applications cannot be developed. Since php does not have any coding development work, all development is based on script technology. Therefore, all source code cannot be compiled. Therefore, the completed application can only be used by itself or internally and cannot be commercialized.

Summary:

Applicable to: familiar with the Unix environment and requires quick application development with minimal investment.

Applicable platform: FreeBSD/Linux/Unix operating system and Apache server applications: applications with high Internet access and fast database development.

Learning method: Internet-based domestic resources: Internet-based source code Resources. you can complete your own applications by referring to such routines. Several recently published php manuals on the market.

Recommended development tools: Home Site/PHPEd

Recommended development environment: FreeBSD 4.1/RedHat 6.1 operating system/Apache 1.3.12/MySQL 3.22/P 200/64 m ram/9G HD

Recommended application environment (minimum): FreeBSD 3.5/MySQL 3.22/Apache 1.3.12/P 200/128 m ram/9G HD

Recommended application environment (best): FreeBSD 3.5/Sybase 11/Apache 1.3.12/p iii 500/512 m ram/18G HD