Linux Tutorial IV

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I believe that a lot of beginners who want to learn Linux are worried about what to look at Linux learning Tutorials Good, the following small series for everyone to collect and organize some of the more important tutorials for everyone to learn, if you want to learn more words, can go to wdlinux school to find more tutorials.

1, Linux system Software installation method

Linux Software Installation, there are two main

1 package Installation

2 Source Code compilation installation

Package installation In fact, is someone else or company, for a specific platform, the system version compiles well, and then pack

Source code compiled, is completely through the source code, manual hand, configuration, compilation, installation

Each has its own length and advantages

Package Installation

1 simple, convenient, fast

2 need to select different packages for specific environments

Source Code Compilation Installation

1 flexible, 17813.html "> Customizable and optimized

2 relatively complex and has a certain basic requirements for operators

3 time is also relatively long, especially some software or larger software, such as MySQL

In the software package installation, different Linux branches, the package is also different

For example, Wdos,centos,redhat use the RPM package.

Like Ubuntu,debian, these are Deb's.

But the source installation, basically all Linux, as well as UNIX are the same, in addition to the parameters

Which is better? No standards, depending on the needs and circumstances

2. About Time zone settings:

To ensure that the time is correct, the time zone should be set correctly. Set correctly only to make time better understood and other aspects of maintenance.

To set the method:

1.

To set the time zone manually:

For example: Set the time in the East eight area

Ln-sf/usr/share/zoneinfo/asia/shanghai

/etc/localtime

Edit/etc/sysconfig/clock zone= "Asia/shanghai"

2.

Setting with graphical commands

System-config-date (mostly limited to redhat and CentOS) or using Tzselect, follow the command prompt.

3, Linux under what is the directory? Absolute directory? Absolute path? Relative directory? Relative path?

Accustomed to Windows friends, all know, C disk, D disk, E disk and so on directory, absolute path These are not what the concept of

But people who are more exposed to computers or have access to DOS or some commands under Windows will generally know

But there is still a c,d,e disk and so on, this windows to the directory of a separate method

But Linux under different, Linux does not have the concept of the letter, all of them are directories and files

A directory is an organization of files, a way to locate files, we need to find out what files or what files to create, all require a directory, because you need to know where to put it, or where to find, so know and understand

Windows has a number of letter points

But Linux has only one root directory, all other directories are in the root directory, or below the lower directory, etc.

Specific directory structure, here does not make detailed, interested students, you can view the relevant books and documents

The main point here is to illustrate absolute directory, absolute path

In fact, the absolute directory, the absolute path is the same thing, but the name is different, I was so understanding

There is also a noun, relative directory, relative path

It's a little bit like a reference in physics.

Use reference to the current directory, that to find or CD, you can use the current directory as a relative directory

What is an absolute catalogue?

Linux is more often hear or see this noun, WDCP also met in the background, such as this article

Http://www.wdlinux.cn/bbs/thread-1506-1-1.html

This article is also because of this article, will appear here

can be so simple to understand

The first character at the beginning of the directory name is the absolute directory

and others can be understood as relative directories, which means that the method is usually. /

Remember two points, one point is current, two points is superior, so on

Let's understand the next few commands.

cd

This command can change the directory to the directory path to go to, such as

Cd/etc

went to the ETC directory, which is to change the current directory command

List current directory

Pwd

For example, we have time to log in to SSH with Root and then execute PWD, which will show

/root

This is our current directory and the user's home directory.

If it is a regular user, it is generally in the filesystem directory, such as

/home/wdlinux

Then we'll understand. Directory, relative directory

For example, we are currently in the/root directory, that is, the current directory

We're going to the/home/wdlinux catalogue.

There are two ways

One is the absolute path method, such as

Cd/home/wdlinux

One is the relative path method, such as

CD. /home/wdlinux

Before two, you can know which is simpler

So, sometimes it's a very efficient way to memorize absolute catalogs and use absolute catalogs.

Beginning to think that two words can be said to clear, but now found that it is not

And it doesn't seem to be clear enough to say so much.

4, Eaccelerator cache removal cleanup and settings

Eaccelerator itself has the function of automatic scavenging, the specific setting options are as follows: eaccelerator.shm_ttl= "600"

When Eaccelerator fails to get the shared memory size of the new script, it deletes all script caches that are inaccessible in the last "Shm_ttl" seconds from shared memory. The default value is "0", which means that no cached files are deleted from the shared spring.

Eaccelerator.shm_prune_period= "600"

When Eaccelerator fails to get the shared memory size of the new script, he attempts to remove cache scripts older than "Shm_prune_period" from shared memory. The default value is "0", which means that no cached files are deleted from the shared spring.

Therefore, if not set to 0, it will automatically clear, if set to 0, it is necessary to manually clear apart

Manual removal, you can directly directory cache directory subdirectory, restart the Web service can be or in the eaccelerator of the panel to clear or

This tutorial is excerpted from Wdlinux forum http://www.wdlinux.cn/bbs/, Welcome to Reprint ~

Related reading:

One of the Linux tutorials

Linux Tutorial II

Linux Tutorial III