來源：Atstudy網校
1.簡介
在Oracle收購Sun后，Java的一系列產品就被整合到Oracle官網中，打開官網乍眼一看也不知道去哪里下載，還的一個一個的摸索嘗試，而且網上大多數都是一些Oracle收購Sun前，或者就是一些老的資料文章，為了避免這些坑，宏哥才決定寫着一篇文章。
JDK是 JAVA 的軟件開發工具包，如果要使用JAVA來進行開發，或者部署基於其開發的應用，那么就需要安裝JDK。本次將在Linux下安裝JDK及配置環境。在以前宏哥也在Linux下安裝過JDK，安裝過程溜得飛起來。結果這次安裝過程中卻是十分的不順，所以才有了這篇文章用來記錄和分享安裝 過程中遇到的問題和心得體會，希望對各位有所幫忙，避免做更多的無用功。
宏哥的環境：
查看Linux環境輸入命令：lsb_release -a
[admin@oftpclient201 ~]$ lsb_release -a LSB Version: :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch Distributor ID: CentOS Description: CentOS Linux release 7.9.2009 (Core) Release: 7.9.2009
2.下載JDK
在安裝之前，檢查是否存在Linux下自帶的OpenJDK，命令：rpm -qa | grep java。若存在，則需要進行卸載，命令：rpm -e --nodeps 卸載的軟件名。
其他方法：
java -version
echo $PATH 看環境變量bai是否配du置了java路徑
find / -name java 查找zhijava文件
JDK歷史版本鏈接：https://www.oracle.com/technetwork/java/javase/archive-139210.html
接着，我們可以通過 wget 命令下載JDK安裝包，或者下載后傳到Linux。我這里下載的安裝包版本是 jdk-8u281-linux-x64.tar.gz 。
2.1使用wget下載JDK8
每次去官網下載JDK有點煩 但是直接使用wget 又得同意協議所以 使用如下的wget就好了(注意是64位的哦)
1.先去官網看一下地址變化 沒有如下 :修改后面的下載地址即可 注意哦~現在和以前變化挺大的，所以宏哥在這里贅述一下具體步驟：
（1）在瀏覽器的地址欄輸入JDK官網地址：https://www.oracle.com/ ，如下圖所示：
（2）鼠標放在product上在下拉菜單中點擊Java，如下圖所示：
（3）然后再點擊“Download Java”，如下圖所示：
（4）下滑頁面找到Java SE8，然后點擊“JDK Download”,如下圖所示：
（5）找到Linux系統的64位的JDK，選中安裝包右鍵，點擊“復制鏈接地址”，如下圖所示：
（6）在xshell上輸入命令wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie"后面加上你剛才復制的下載鏈接
2.然后使用下面的wget下載就好了~(注意文件的后綴，有時候不可以直接解壓需要重命名后綴名哦)
wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u171-b11/512cd62ec5174c3487ac17c61aaa89e8/jdk-8u171-linux-x64.tar.gz
3.解壓安裝包
創建一個文件夾，用於存放JDK安裝包，然后解壓到該目錄下。
創建文件夾：mkdir /usr/JDK
進入文件夾：cd /usr/JDK
將下載好的壓縮文件剪貼到創建好的文件夾下：mv jdk-8u281-linux-x64.tar.gz /usr/JDK/
解壓：tar -zxvf jdk-8u281-linux-x64.tar.gz
可以看到，本次解壓到了當前目錄 /usr/JDK/jdk1.8.0_281下。
4.配置環境
解壓完成之后，我們要配置下環境變量，通過 vim 命令修改配置文件 /etc/profile 來設置環境變量。
vim /etc/profile
在文件最后一行，輸入 i 進入編輯模式，添加以下內容，然后按 Esc 退出編輯模式，再輸入 :wq 保存並退出。
export JAVA_HOME=/usr/JDK/jdk1.8.0_281 export JRE_HOME=${JAVA_HOME}/jre export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib export PATH=${JAVA_HOME}/bin:$PATH
設置完之后，如果要使環境變量立即生效，需要通過命令：source /etc/profile，重新加載配置文件。
5.驗證是否安裝成功
所有都配置好了，我們需要驗證下是否安裝成功。
依次輸入 java -version、java、javac，不會出現報錯並且顯示出 jdk版本號及 java/javac相關命令參數說明界面。
[admin@oftpclient201 ~]$ java -version java version "1.8.0_281" Java(TM) SE Runtime Environment (build 1.8.0_281-b09) Java HotSpot(TM) 64-Bit Server VM (build 25.281-b09, mixed mode) [admin@oftpclient201 ~]$ java Usage: java [-options] class [args...] (to execute a class) or java [-options] -jar jarfile [args...] (to execute a jar file) where options include: -d32 use a 32-bit data model if available -d64 use a 64-bit data model if available -server to select the "server" VM The default VM is server. -cp <class search path of directories and zip/jar files> -classpath <class search path of directories and zip/jar files> A : separated list of directories, JAR archives, and ZIP archives to search for class files. -D<name>=<value> set a system property -verbose:[class|gc|jni] enable verbose output -version print product version and exit -version:<value> Warning: this feature is deprecated and will be removed in a future release. require the specified version to run -showversion print product version and continue -jre-restrict-search | -no-jre-restrict-search Warning: this feature is deprecated and will be removed in a future release. include/exclude user private JREs in the version search -? -help print this help message -X print help on non-standard options -ea[:<packagename>...|:<classname>] -enableassertions[:<packagename>...|:<classname>] enable assertions with specified granularity -da[:<packagename>...|:<classname>] -disableassertions[:<packagename>...|:<classname>] disable assertions with specified granularity -esa | -enablesystemassertions enable system assertions -dsa | -disablesystemassertions disable system assertions -agentlib:<libname>[=<options>] load native agent library <libname>, e.g. -agentlib:hprof see also, -agentlib:jdwp=help and -agentlib:hprof=help -agentpath:<pathname>[=<options>] load native agent library by full pathname -javaagent:<jarpath>[=<options>] load Java programming language agent, see java.lang.instrument -splash:<imagepath> show splash screen with specified image See http://www.oracle.com/technetwork/java/javase/documentation/index.html for more details. [admin@oftpclient201 ~]$ javac Usage: javac <options> <source files> where possible options include: -g Generate all debugging info -g:none Generate no debugging info -g:{lines,vars,source} Generate only some debugging info -nowarn Generate no warnings -verbose Output messages about what the compiler is doing -deprecation Output source locations where deprecated APIs are used -classpath <path> Specify where to find user class files and annotation processors -cp <path> Specify where to find user class files and annotation processors -sourcepath <path> Specify where to find input source files -bootclasspath <path> Override location of bootstrap class files -extdirs <dirs> Override location of installed extensions -endorseddirs <dirs> Override location of endorsed standards path -proc:{none,only} Control whether annotation processing and/or compilation is done. -processor <class1>[,<class2>,<class3>...] Names of the annotation processors to run; bypasses default discovery process -processorpath <path> Specify where to find annotation processors -parameters Generate metadata for reflection on method parameters -d <directory> Specify where to place generated class files -s <directory> Specify where to place generated source files -h <directory> Specify where to place generated native header files -implicit:{none,class} Specify whether or not to generate class files for implicitly referenced files -encoding <encoding> Specify character encoding used by source files -source <release> Provide source compatibility with specified release -target <release> Generate class files for specific VM version -profile <profile> Check that API used is available in the specified profile -version Version information -help Print a synopsis of standard options -Akey[=value] Options to pass to annotation processors -X Print a synopsis of nonstandard options -J<flag> Pass <flag> directly to the runtime system -Werror Terminate compilation if warnings occur @<filename> Read options and filenames from file [admin@oftpclient201 ~]$
6.小結
安裝過程中宏哥為了避免麻煩不是在Windows上直接安裝好然后再上傳到Linux上，而是直接用weget命令直接安裝的，結果遇到如下一系列的問題：
（1）wget+復制好的下載地址
[admin@oftpclient201 ~]$ wget https://download.oracle.com/otn/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz--2021-02-25 15:25:47-- https://download.oracle.com/otn/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gzResolving download.oracle.com (download.oracle.com)... 184.50.93.194Connecting to download.oracle.com (download.oracle.com)|184.50.93.194|:443... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: https://edelivery.oracle.com/akam/otn/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz [following] --2021-02-25 15:25:48-- https://edelivery.oracle.com/akam/otn/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz Resolving edelivery.oracle.com (edelivery.oracle.com)... 184.30.17.110, 2600:1400:c000:482::366, 2600:1400:c000:488::366 Connecting to edelivery.oracle.com (edelivery.oracle.com)|184.30.17.110|:443... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: https://login.oracle.com:443/oam/server/obrareq.cgi?encquery%3D4PIlzUXFrmsJOQa3pTVPbD8FleZqJX%2Bqm5A%2BmXnkil9RBAqGW%2Bd5Z3FgcL03OH1P%2FL%2FPpBosJhXNi%2BaNvJ5gWRCWlkmsTghONwL1Ixk8tJ66nMfQItxzYLYEA6Ae%2F4xxJtk3wvyzw4EzT%2B88B%2BHNgKJs6w67VGaR6kHqcVem1SIW%2Fxxps6xSH%2Bqe9li%2BI0FMXUw2Dptss7A0VEtYvTTpUHnLteqH9Wt2TJiK%2F8%2BVmtRUTs5Y2YaOxZqrr6VcBsyAi83RSY1PKFiJChmpxiao1%2Bomcz9PKzc04xMlEg2hVJFAoTxUkyPKCWWEmipcbGPfcQOJYVrfjGqqmAGIDBfUfmpAGcQf21ceJqkm739Jf%2Bue68iM7YPcI7WOdFjxWLG9Ykj2NVjTwjmCDzZUsBFzMiT8SeXRqH7dTevRYZuzg0b%2F8PZNqeTjzZ5LHzG6WA1%2FlWsXpwgBuB3OklWgZs5HBg25Mx5Uqdu%2BHzc6qzaGNlWKrQj5pWUvGpz1rVPB23SywqnzFy9iUm4I%2FlXYeJDzJQ%3D%3D%20agentid%3Dedelivery-extprod%20ver%3D1%20crmethod%3D2&ECID-Context=1.005j2GF_XvzFo2KimTctkJ00023d00wI1l%3BkXjE [following] --2021-02-25 15:25:50-- https://login.oracle.com/oam/server/obrareq.cgi?encquery%3D4PIlzUXFrmsJOQa3pTVPbD8FleZqJX%2Bqm5A%2BmXnkil9RBAqGW%2Bd5Z3FgcL03OH1P%2FL%2FPpBosJhXNi%2BaNvJ5gWRCWlkmsTghONwL1Ixk8tJ66nMfQItxzYLYEA6Ae%2F4xxJtk3wvyzw4EzT%2B88B%2BHNgKJs6w67VGaR6kHqcVem1SIW%2Fxxps6xSH%2Bqe9li%2BI0FMXUw2Dptss7A0VEtYvTTpUHnLteqH9Wt2TJiK%2F8%2BVmtRUTs5Y2YaOxZqrr6VcBsyAi83RSY1PKFiJChmpxiao1%2Bomcz9PKzc04xMlEg2hVJFAoTxUkyPKCWWEmipcbGPfcQOJYVrfjGqqmAGIDBfUfmpAGcQf21ceJqkm739Jf%2Bue68iM7YPcI7WOdFjxWLG9Ykj2NVjTwjmCDzZUsBFzMiT8SeXRqH7dTevRYZuzg0b%2F8PZNqeTjzZ5LHzG6WA1%2FlWsXpwgBuB3OklWgZs5HBg25Mx5Uqdu%2BHzc6qzaGNlWKrQj5pWUvGpz1rVPB23SywqnzFy9iUm4I%2FlXYeJDzJQ%3D%3D%20agentid%3Dedelivery-extprod%20ver%3D1%20crmethod%3D2&ECID-Context=1.005j2GF_XvzFo2KimTctkJ00023d00wI1l%3BkXjE Resolving login.oracle.com (login.oracle.com)... 209.17.4.8 Connecting to login.oracle.com (login.oracle.com)|209.17.4.8|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 4103 (4.0K) [text/html] Saving to: ‘jdk-8u281-linux-x64.tar.gz.1’ 100%[==============================================================================================================================================================================>] 4,103 17.6KB/s in 0.2s 2021-02-25 15:25:51 (17.6 KB/s) - ‘jdk-8u281-linux-x64.tar.gz.1’ saved [4103/4103] [admin@oftpclient201 ~]$
從上圖看着好像是下載成功了，但是宏哥在解壓的時候有報錯了，報錯如下：
[admin@oftpclient201 ~]$ tar -zxvf jdk-8u281-linux-x64.tar.gz gzip: stdin: not in gzip format tar: Child returned status 1 tar: Error is not recoverable: exiting now [admin@oftpclient201 ~]$
從上圖的報錯可以發現說是壓縮包不完整，宏哥好奇既然下載成功怎么會是不完整的了，於是宏哥看了一下壓縮包的大小，如下所示才4.1K，
[admin@oftpclient201 ~]$ ll -lh total 16K -rw-rw-r--. 1 admin admin 0 Feb 25 15:25 ] -rw-rw-r--. 1 admin admin 4.1K Feb 25 15:24 jdk-8u281-linux-x64.tar.gz -rw-rw-r--. 1 admin admin 39 Feb 2 16:20 test.txt -rw-rw-r--. 1 admin admin 78 Feb 2 16:21 t.zip [admin@oftpclient201 ~]$
這個與Oracle官網顯示的大小100多M差太多了，所以確定是下載不成功而且回過頭來看一下下載時間幾乎零點幾秒就下載完成了，更加確定下載的壓縮包是不完整的。
查了資料說是由於Oracle需要accept license、cookie，所以需要給wget帶如下參數即可，於是就有了第二種方法的嘗試
（2）wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie"+復制好的下載地址
[admin@oftpclient201 ~]$ wget --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie;" https://download.oracle.com/otn/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz --2021-02-25 15:56:55-- https://download.oracle.com/otn/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz Resolving download.oracle.com (download.oracle.com)... 92.123.228.99 Connecting to download.oracle.com (download.oracle.com)|92.123.228.99|:443... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: https://edelivery.oracle.com/akam/otn/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz [following] --2021-02-25 15:56:56-- https://edelivery.oracle.com/akam/otn/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz Resolving edelivery.oracle.com (edelivery.oracle.com)... 23.76.64.181, 2a02:26f0:a00:3be::366, 2a02:26f0:a00:385::366 Connecting to edelivery.oracle.com (edelivery.oracle.com)|23.76.64.181|:443... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: https://login.oracle.com:443/oam/server/obrareq.cgi?encquery%3DSyDVndLEpx6WpSyvf2If6hV7vdEN%2BIvCiOpWhz5xUgWJKCBA4mYVvksWHq4vohW6kyMvXAjWfJyda2XrAkGPdxyVK9FcqsRYhvs1DZDEbVLAtEnG5a2Zw2R07iGjm1v79FPjjXyDKSR%2B52%2F0qdEhmP6pPdLPEjhEHVNXr1usKyMmhI0FeYrjn7YcQLjvVOGbZsVR6%2Bu0hqU8jZPxDtXpo8zANJoPdEGxwOiThOVkCWm2cvpOC3Y0QBICZ1yvcWtvTOSHUwZMZgeEp2EdCqlHwH0nm0JWFAKHf6qL9RI1Qs0ZRNth%2FkzjYDLrlY%2B9D1%2BESsQHCAUa2kRHwKXf89u%2BbIUMT2o0xqFtzvJLgQjlG9pUZ7JIxHYVZXzRc1lQwiJove8sjHWNOaujjaryNEGMH5WfiqCp8Y6ogcgd%2B4qNoBLOz7oCOsZkYrzAyfq7481ei7PPvESoBRw6ezsmB06LZt1YHnpf%2BGwf2q33TckhLOVb8C6Bs3bwkmhBfwhDNMnGd%2BonHh%2Fg7kcNscjuTkbwFw%3D%3D%20agentid%3Dedelivery-extprod%20ver%3D1%20crmethod%3D2&ECID-Context=1.005j2HyusRcFo2KimTXvWJ0002ZZ00IcIc%3BkXjE [following] --2021-02-25 15:56:57-- https://login.oracle.com/oam/server/obrareq.cgi?encquery%3DSyDVndLEpx6WpSyvf2If6hV7vdEN%2BIvCiOpWhz5xUgWJKCBA4mYVvksWHq4vohW6kyMvXAjWfJyda2XrAkGPdxyVK9FcqsRYhvs1DZDEbVLAtEnG5a2Zw2R07iGjm1v79FPjjXyDKSR%2B52%2F0qdEhmP6pPdLPEjhEHVNXr1usKyMmhI0FeYrjn7YcQLjvVOGbZsVR6%2Bu0hqU8jZPxDtXpo8zANJoPdEGxwOiThOVkCWm2cvpOC3Y0QBICZ1yvcWtvTOSHUwZMZgeEp2EdCqlHwH0nm0JWFAKHf6qL9RI1Qs0ZRNth%2FkzjYDLrlY%2B9D1%2BESsQHCAUa2kRHwKXf89u%2BbIUMT2o0xqFtzvJLgQjlG9pUZ7JIxHYVZXzRc1lQwiJove8sjHWNOaujjaryNEGMH5WfiqCp8Y6ogcgd%2B4qNoBLOz7oCOsZkYrzAyfq7481ei7PPvESoBRw6ezsmB06LZt1YHnpf%2BGwf2q33TckhLOVb8C6Bs3bwkmhBfwhDNMnGd%2BonHh%2Fg7kcNscjuTkbwFw%3D%3D%20agentid%3Dedelivery-extprod%20ver%3D1%20crmethod%3D2&ECID-Context=1.005j2HyusRcFo2KimTXvWJ0002ZZ00IcIc%3BkXjE Resolving login.oracle.com (login.oracle.com)... 209.17.4.8 Connecting to login.oracle.com (login.oracle.com)|209.17.4.8|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 4149 (4.1K) [text/html] Saving to: ‘jdk-8u281-linux-x64.tar.gz’ 100%[==============================================================================================================================================================================>] 4,149 --.-K/s in 0s 2021-02-25 15:56:59 (24.7 MB/s) - ‘jdk-8u281-linux-x64.tar.gz’ saved [4149/4149] [admin@oftpclient201 ~]$
按方法一確認以后發現下載的壓縮包還是不完整，查了資料說是按這種方法就可以，也有的說是這種方法已經過時了。還有的說是wget命令有缺陷不會重定向，但是抓包是發現網頁中點擊下載會有重定向的請求，...等等各種各樣的說法，第二天宏哥正要老老實實的在Oracle注冊、登錄賬號（太麻煩）據說注冊、登錄賬號后，復制的下載鏈接中會自帶cookie、協議和安全認證，然后用wget命令+上此下載鏈接可以下載成功，但是宏哥覺得有點麻煩，這種方法就沒嘗試，你如果有興趣的話，童鞋們或者小伙伴自己可以嘗試一下按宏哥說的是否可以成功下載壓縮包。，然后下載Linux的JDK安裝包，然后再上傳到Linux系統中。但是宏哥這個人比較懶吧，也比較不甘心，所以再次決定再查查資料。結果百度查詢了半天左右，經過反復的摸索終於找到一個靠譜的答案。網上那些太多的都是復制來復制去，都不能解決實質性問題。
（3）在方法二的基礎上將下載地址中的otn修改成otn-pub
[admin@oftpclient201 ~]$ wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" https://download.oracle.com/otn-pub/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz --2021-02-25 16:10:40-- https://download.oracle.com/otn-pub/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz Resolving download.oracle.com (download.oracle.com)... 184.86.92.87 Connecting to download.oracle.com (download.oracle.com)|184.86.92.87|:443... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: https://edelivery.oracle.com/otn-pub/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz [following] --2021-02-25 16:10:41-- https://edelivery.oracle.com/otn-pub/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz Resolving edelivery.oracle.com (edelivery.oracle.com)... 23.76.87.214, 2600:1400:c000:482::366, 2600:1400:c000:488::366 Connecting to edelivery.oracle.com (edelivery.oracle.com)|23.76.87.214|:443... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: https://download.oracle.com/otn-pub/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz?AuthParam=1614240762_cf401250c965e2946ab43486aa6c2db3 [following] --2021-02-25 16:10:42-- https://download.oracle.com/otn-pub/java/jdk/8u281-b09/89d678f2be164786b292527658ca1605/jdk-8u281-linux-x64.tar.gz?AuthParam=1614240762_cf401250c965e2946ab43486aa6c2db3 Connecting to download.oracle.com (download.oracle.com)|184.86.92.87|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 143722924 (137M) [application/x-gzip] Saving to: ‘jdk-8u281-linux-x64.tar.gz’ 100%[==============================================================================================================================================================================>] 143,722,924 2.67MB/s in 57s 2021-02-25 16:11:40 (2.41 MB/s) - ‘jdk-8u281-linux-x64.tar.gz’ saved [143722924/143722924] [admin@oftpclient201 ~]$ ll -h
從上圖可以看出下載時間是57s,雖然這個時間與網速有關系，但是大致感覺時間也差不多了。因此宏哥判斷這次是真的解決了，安裝包下載成功了。
和宏哥來再次看一下壓縮的安裝包的大小是138M，和官網展示的大小也差不多，預示着下載成功，問題解決
[admin@oftpclient201 ~]$ ll -h total 138M -rw-rw-r--. 1 admin admin 0 Feb 25 16:09 ] -rw-rw-r--. 1 admin admin 138M Dec 11 03:12 jdk-8u281-linux-x64.tar.gz -rw-rw-r--. 1 admin admin 39 Feb 2 16:20 test.txt -rw-rw-r--. 1 admin admin 78 Feb 2 16:21 t.zip [admin@oftpclient201 ~]$
7.拓展
7.1linux下如何查看已安裝的centos版本信息
1.Linux查看當前操作系統版本信息 cat /proc/version
[admin@oftpclient201 ~]$ cat /proc/version Linux version 3.10.0-1160.11.1.el7.x86_64 (mockbuild@kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (GCC) ) #1 SMP Fri Dec 18 16:34:56 UTC 2020 [admin@oftpclient201 ~]$
2.Linux查看版本當前操作系統內核信息 uname -a
[admin@oftpclient201 ~]$ uname -a Linux oftpclient201.test.cedex.cn 3.10.0-1160.11.1.el7.x86_64 #1 SMP Fri Dec 18 16:34:56 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
3.linux查看版本當前操作系統發行信息 cat /etc/issue 或 cat /etc/centos-release
[admin@oftpclient201 ~]$ cat /etc/centos-release CentOS Linux release 7.9.2009 (Core)
4.Linux查看cpu相關信息，包括型號、主頻、內核信息等 cat /etc/cpuinfo
[admin@oftpclient201 ~]$ cat /proc/cpuinfo processor : 0 #數值為0表示第1顆cpu vendor_id : GenuineIntel cpu family : 6 model : 58 model name : Intel(R) Core(TM) i5-3320M CPU @ 2.60GHz stepping : 9 microcode : 0x15 cpu MHz : 2594.170 cache size : 3072 KB physical id : 0 siblings : 1 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf eagerfpu pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm epb fsgsbase tsc_adjust smep dtherm ida arat pln pts bogomips : 5188.34 clflush size : 64 cache_alignment : 64 address sizes : 42 bits physical, 48 bits virtual power management: processor : 1 #數值為1表示第2顆cpu vendor_id : GenuineIntel cpu family : 6 model : 58 model name : Intel(R) Core(TM) i5-3320M CPU @ 2.60GHz stepping : 9 microcode : 0x15 cpu MHz : 2594.170 cache size : 3072 KB physical id : 2 siblings : 1 core id : 0 cpu cores : 1 apicid : 2 initial apicid : 2 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf eagerfpu pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm epb fsgsbase tsc_adjust smep dtherm ida arat pln pts bogomips : 5188.34 clflush size : 64 cache_alignment : 64 address sizes : 42 bits physical, 48 bits virtual power management:
processor ：系統中邏輯處理核的編號。對於單核處理器，則課認為是其CPU編號，對於多核處理器則可以是物理核、或者使用超線程技術虛擬的邏輯核
vendor_id ：CPU制造商
cpu family ：CPU產品系列代號
model ：CPU屬於其系列中的哪一代的代號
model name：CPU屬於的名字及其編號、標稱主頻
stepping ：CPU屬於制作更新版本
cpu MHz ：CPU的實際使用主頻
cache size ：CPU二級緩存大小
physical id ：單個CPU的標號
siblings ：單個CPU邏輯物理核數
core id ：當前物理核在其所處CPU中的編號，這個編號不一定連續
cpu cores ：該邏輯核所處CPU的物理核數
apicid ：用來區分不同邏輯核的編號，系統中每個邏輯核的此編號必然不同，此編號不一定連續
fpu ：是否具有浮點運算單元（Floating Point Unit）
fpu_exception ：是否支持浮點計算異常
cpuid level ：執行cpuid指令前，eax寄存器中的值，根據不同的值cpuid指令會返回不同的內容
wp ：表明當前CPU是否在內核態支持對用戶空間的寫保護（Write Protection）
flags ：當前CPU支持的功能
bogomips ：在系統內核啟動時粗略測算的CPU速度（Million Instructions Per Second）
clflush size ：每次刷新緩存的大小單位
cache_alignment ：緩存地址對齊單位
address sizes ：可訪問地址空間位數
5.Linux查看版本說明當前CPU運行在32bit模式下(但不代表CPU不支持64bit)
[admin@oftpclient201 etc]$ getconf LONG_BIT 64
7.2uname的使用
uname命令用於打印當前系統相關信息（內核版本號、硬件架構、主機名稱和操作系統類型等）。
uname -a顯示全部信息 -m或--machine：顯示電腦類型； -r或--release：顯示操作系統的發行編號； -s或--sysname：顯示操作系統名稱； -v：顯示操作系統的版本； -p或--processor：輸出處理器類型或"unknown"； -i或--hardware-platform：輸出硬件平台或"unknown"； -o或--operating-system：輸出操作系統名稱； --help：顯示幫助； --version：顯示版本信息。
7.3查看Linux版本
1.查看系統版本信息的命令 lsb_release -a
(使用命令時提示command not found,需要安裝yum install redhat-lsb -y)
[admin@oftpclient201 etc]$ [admin@oftpclient201 etc]$ lsb_release -a LSB Version: :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch Distributor ID: CentOS Description: CentOS Linux release 7.9.2009 (Core) Release: 7.9.2009 Codename: Core
注:這個命令適用於所有的linux，包括RedHat、SUSE、Debian等發行版。
2.查看centos版本號 cat /etc/issue
[admin@oftpclient201 etc]$ cat /etc/issue
\S
Kernel \r on an \m
[admin@oftpclient201 etc]$
3.使用 file /bin/ls
[admin@oftpclient201 etc]$ file /bin/ls /bin/ls: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=c8ada1f7095f6b2bb7ddc848e088c2d615c3743e, stripped [admin@oftpclient201 etc]$