The installation of Apache and the resolution of the problem such as Apr

1) command to view Apache installation and its version number
$RPM-Q httpd
If an installed Apache is present, its information is listed

2) formally start Apache installation
2.1) Download the HTTPD package. Go to Apache's httpd official website Https://httpd.apache.org/download.cgi#apache24, find the required version of HTTPD,
The author chooses the httpd-2.4.20.tar.gz
2.2) Decompression httpd-2.4.20.tar.gz
Use the $tar zxvf httpd-2.4.20.tar.gz to extract the files to the current folder.
2.3) due to direct installation may cause some problems, the problem is as follows:
Checking for APR ... no
Configure:error:APR not found. Please read the documentation
So before installing, these modules can be installed, in the installation of httpd
2.3.1) Install Apr. Download apr-1.4.5.tar.gz by the following address
wget http://archive.apache.org/dist/apr/apr-1.4.5.tar.gz
Follow the steps below to install
1. Unzip with: $tar ZXVF apr-1.4.5.tar.gz
2. Go to the apr-1.4.5 folder and use the./configure--PREFIX=/USR/LOCAL/APR to configure
3. $make && make install for compilation
2.3.2) Install Apr-util. Download apr-util-1.3.12.tar.gz via the address below
wget http://archive.apache.org/dist/apr/apr-util-1.3.12.tar.gz
Follow the steps below to install
1. Unzip with: $tar ZXVF apr-util-1.3.12.tar.gz
2. Go to the Apr-util-1.3.12 folder and use the./configure--prefix=/usr/local/apr-with-apr=/usr/local/apr/bin/apr-1-config to configure
3. $make && make install for compilation
2.3.3) Install Pcre. Download Pcre-8.10.zip via the address below
wget Http://jaist.dl.sourceforge.net/project/pcre/pcre/8.10/pcre-8.10.zip

Follow the steps below to install
1. Extract with: $unzip pcre-8.10.zip
2. Go to the Pcre-8.10 folder and use the./configure--prefix=/usr/local/pcre--disable-shared--with-pic to configure (./configure--prefix=/usr /local/pcre)
3. $make && make install for compilation
3) Compile and install Apache
1. Enter 2nd) step, unzip the httpd.2.4.20 folder,
2. Using the./configure--prefix=/usr/local/apache2--enable-so--with-apr=/usr/local/apr--with-apr-util=/usr/local/ apr-util/--with-pcre=/usr/local/pcre for configuration
3. $make && make install for compilation

The above steps are the basic steps for installing Apache, and some of the common problems that may arise are resolved

The installation of Apache and the resolution of the problem such as Apr