Article Directory
One, Linux application basics
(1) The relationship between application programs and system commands
| Roles | System command | application |
|---|---|---|
| File location | Generally in the /bin and /sbin directories, or shell internal commands | Usually in /usr/bin, lusr/sbin and /usr/local/bin, /usr/local/sbin |
| The main purpose | Complete basic management of the system, such as IP configuration tools | Complete other relatively independent auxiliary tasks, such as web browsers |
| Applicable environment | Generally only run in the character operation interface | According to actual needs, some programs can be run in the graphical interface |
| Run format | Generally include command words, command options and command parameters | Usually there is no fixed execution format, which is defined by the program developer |
Enter the / directory to view the directory files, and found that bin and sbin are actually soft links, pointing to user/bin and user/sbin, where user/bin and user/sbin are in the path environment variable. When doing source installation, the program commands will be made a soft link to user/bin and user/sbin.
(2) Directory structure of typical applications
| file type | Save directory | Description |
|---|---|---|
| Ordinary executable program file | /usr/bin | Executable by all users |
| Server program, management program file | /usr/sbin | Only the administrator can execute |
| Application configuration file | /etc | Applications installed via rpm or yum |
| Log file | / var / log | System log |
| Application Reference Document File | /usr/share/doc | Reference documents and other data about the application |
| Application man page file | /usr/share/man | Man pages for executable files and configuration files |
(3) Common package types
| file type | Save directory |
|---|---|
| RPM package | The extension is ".rpm", suitable for RHEL, CentOS and other systems |
| DEB software package | The extension is ".deb", suitable for Ubuntu, Debian and other systems |
| Source code package | Compressed packages generally in the format of ".tar.g2" and ".tar.bz2" contain the original code of the program and need to be compiled and installed |
| Package with installer | The extensions of the software packages vary, mostly in TarBall format; executable programs or script files for installation are provided in the software package, such as install.sh, setup, etc. |
Commonly used in Linux systems are RPM software packages and source code software packages
Two, RPM
(1) RPM package management tool
1, RPM Package Manager Red-Hat Package Manager
put forward by the company Red Hat, by many Linux distributions used
to establish a unified database file
detailed records package install, uninstall, upgrade, change information
automatically analyze package dependencies
2, RPM software package
Software material reference: http://www.rpm.org
General naming format: bash-4.2.46-28.el7.x86 _64.rpm
(where bash represents the software name, 4.2.46 represents the version number, 28. Represents the number of releases, el7 represents the supported system, x86 _64 represents the supported hardware platform, and .rpm represents the extension)
(2) The format of rpm command
1. The rpm command can realize almost all the management functions of the RPM software package.
2. Execute the "man rpm" command to get detailed help information about the rpm command.
3. The rpm command function
query and verify the relevant information of the RPM package
installation, upgrade, Uninstall RPM software package
maintain and rebuild RPM database information and other comprehensive management operations
(3) Query RPM software package information
1. Query information about installed RPM software
rpm -q [子选项] 软件名
Common options
-qa, -qi, -ql, -qf, -qc, -qd
2, query the information in the RPM package file
rpm -qp[子选项] RPM包文件
Common options
-qpi、 -qpl、 -qpc、 -qpd
(4) Query information about installed rpm software
rpm -q software name# query whether the specified software is installed
rpm -qi software name# show the detailed information of the specified software installed
rpm -ql software name# show the file list of the specified software installed
rpm -qc software name#list The configuration file of the specified software that has been installed
rpm -qd software name#lists the location of the software package documentation of the specified software that has been installed
rpm -qR software name#lists the dependent software packages and files of the specified software that have been installed
rpm -qf File or Directory#Query which installation package the specified software has been installed belongs to
rpm -qa #Display the list of all software installed in rpm mode in the current system
rpm -qa I grep -i postfix #Query whether the software postfix has been installed
Query the information in the RPM package file that is not installed
rpm -qpi RPM包FILENAME#Query the detailed information of the specified software package
rpm -qpl RPM包FILENAME#query the file list of the specified software package
rpm -qpc RPM包FILENAME#query specified The configuration file of the software package
rpm -qpd RPM package file name#Query the location of the software package document of the specified software package
Using rpm -q software name (check whether the specified software has been installed), you can find out whether the software you want to use has been installed.
Use the rpm -qi software name to display the detailed information of the installed postfix (specified software).
Use rpm -ql software name, you can display a list of all files related to postfix (specified software).
rpm -qa (display the list of all software installed in rpm mode in the current system) It can be used with the "grep" command to achieve the effect of filtering files and displaying them.
Use the rpm -qf file or directory (note that the software package cannot be added here), you can query which installation package the specified software belongs to
Use rpm -qa I grep -i postfix to query whether the software (postfix) has been installed
(Four), installation, upgrade, RPM software package format:
rpm [选项] RPM包文件
rpm -ivh RPM软件包
Common options:
-i: install a new RMM software package.
-U: Upgrade a software package, if it has not been installed, install it.
-F: Upgrade a certain software package, if it has not been installed, then abandon the installation.
-h: In the process of installing or upgrading the software package, the installation progress will be displayed with "#".
-v: Display detailed information during software installation.
--Force: force to install a certain package, such as installing an older package
-e: Uninstall the software package with the specified name.
-Nodeps: When installing or upgrading or uninstalling a software package, it does not check the dependencies with other software packages.
Commonly used rpm -ivh RPM software package to install a software can display detailed information and installation progress during the installation process:
Install the software Tree in Packages in the temporary mount directory mnt. First check the tree information, find the software package that needs to be installed, and then install it using rmp -ivh tree-1.6.0-10.el7.x86_64.rpm.
(5) Maintain RPM database
1. Rebuild the RPM database
When the RPM database is damaged, it can be repaired by rebuilding the RPM database
rpm --rebuilddb 或者 rpm --initdb
2. Import verification public key
Before importing the public key file for digital signature verification, an error will be reported when installing part of the RPM software package in the CD. Need to import the public key file located in the root directory of the CD into the RPM database
mount /dev/sr0 /mnt/
rpm --import /mnt/RPM-GPG-KEY-Centos-7
The public key file is stored in the CD root directory mnt:
Three, source code compilation overview
(1) Tarball packet
1、tar.gz和.tar.bz2格式居多
2、软件素材参考: http://sourceforge.net
(Two), integrity check
md5sum校验工具
(3) Confirm the source code compilation environment
**需安装支持C/C++程序语言的编译器,如：gcc、gcc-c++、 make、......**
(4) Use yum to solve the problem of source installation dependencies
To install the source code software package, you need to compile and install, and you need to install a compiler that supports c and c++ programming languages, such as gcc. gcc-c++, make.
If you use rpm to install, you need to install multiple dependent packages first, which will be cumbersome. Here you can use yum to perform one-click installation.
First configure the local yum source warehouse:
mount /dev/cdrom /mnt/ #把光盘挂载到/mnt目录下
cd /etc/yum.repos.d/ #进入到/etc下的yum.repos.d的目录下
mkdir repos.bak #创建一个叫做repos.bak的新目录
mv *.repo repos.bak #将带有.repo的所有文件移动到repos.bak目录下
cd /etc/yum.repos.d/
vim local.repo
[local] #仓库类别
name=local #仓库名称
baseurl=file:///mnt #指定URL访问路径为光盘挂载目录（前面两个//是固定格式，后面一个/是目录）
enabled=1 #开启此yum源,此为默认项,可省略
gpgcheck=0 #不验证软件包的签名
yum clean all && yum makecache #删除yum缓存并更新（可分两步进行）
Create yum warehouse as follows:
yum常用的操作命令:
yum -y install 软件名 #安装、升级软件包, "-y"选项表示自动确认
yum -y remove 软件名 #卸载软件包,可自动解决其依赖关系
yum -y update 软件名 #升级软件包
yum list #查询yum中所有的软件包列表
yum list installed #查询yum仓库中已安装的软件包
yum list available #查询yum仓库中尚未安装的软件包
yum list updates #查询yum仓库中可以升级版本的软件包
yum info 软件名 #查询软件包的描述信息
yum info httpd #查询阿帕奇软件包的描述信息
yum search [all] 关键词 #根据某个关键词来查找相关的软件包
yum search all httpd
yum whatprovides 命令 #查询命令属于哪个软件包
yum whatprovides netstat
When mounting disks, be aware that the disks on the virtual machine need to be connected.
mount is the mount command; /dev/cdrom is the CD; mnt is the temporary mount directory. After mounting, it is read-only and cannot be executed:
Install Apache software with yum -y install:
Use yum -y remove to delete Apache:
Use yum info to query package information:
Use yum to install the compiler:
yum install -y gcc gcc-c++ make
The basic process of compiling and installing:
1), tar unpacking
tar zxvf/jxvf xxx.tar.gz/xxx.tar.bz2 -C 目标路径
2) Configure the software module (installation path, enable or disable module functions, user settings for managing service processes)
./configure --prefix=target path (where the software is installed)
3) Compile (convert the source code into a Program executed)
make
4) install
make install
Use the yum method to install the compiler: (Because the source code installation software requires C and C++ environments, you need to install these two compilers)
