alternatives命令使用方法
alternatives是Linux下的一个功能强大的命令。仅仅能在root权限下运行。如系统中有几个命令功能十分相似,却又不能任意删除,那么能够用 alternatives 来指定一个全局的设置。alternatives经常使用于同一个系统中安装同一软件的多个版本号。比方为了开发须要,我须要安装JDK1.4.2,同一时候还须要JDK1.6.10,我怎么样才干忽略安装路径,依照我自己的意思,使用我想要的java版本号呢?以下为您一一道来。alternatives的命令行运行例如以下:[root@localhost tools]# alternatives alternatives version 1.3.36 - Copyright (C) 2001 Red Hat, Inc.This may be freely redistributed under the terms of the GNU Public License.usage: alternatives --install <link> <name> <path> <priority> [--initscript <service>] [--slave <link> <name> <path>]* alternatives --remove <name> <path> alternatives --auto <name> alternatives --config <name> alternatives --display <name> alternatives --set <name> <path>common options: --verbose --test --help --usage --version --altdir <directory> --admindir <directory>说明:alternatives --install <link> <name> <path> <priority>当中,install表示安装link是符号链接name则是标识符path是运行文件的路径priority则表示优先级以java的安装为例,我的Fedora 8下自带了两种java版本号,分别例如以下: Selection Command-----------------------------------------------* 1 /usr/lib/jvm/jre-1.7.0-icedtea/bin/java 2 /usr/lib/jvm/jre-1.5.0-gcj/bin/java我在文件夹/tools/jdk安装了java version "1.4.2_19"[root@localhost test]# alternatives --install /usr/bin/java java /tools/jdk/bin/java 3[root@localhost test]# alternatives --config javaThere are 3 programs which provide 'java'. Selection Command-----------------------------------------------*+ 1 /usr/lib/jvm/jre-1.7.0-icedtea/bin/java 2 /usr/lib/jvm/jre-1.5.0-gcj/bin/java 3 /tools/jdk/bin/javaEnter to keep the current selection[+], or type selection number: 3我还在文件夹/tools/jdk6下安装了java version "1.6.0_12"[root@localhost test]# alternatives --install /usr/bin/java java /tools/jdk6/bin/java 4[root@localhost test]# alternatives --config javaThere are 4 programs which provide 'java'. Selection Command-----------------------------------------------* 1 /usr/lib/jvm/jre-1.7.0-icedtea/bin/java 2 /usr/lib/jvm/jre-1.5.0-gcj/bin/java + 3 /tools/jdk/bin/java 4 /tools/jdk6/bin/javaEnter to keep the current selection[+], or type selection number: 4用alternatives --config java就能够选择你想要的Java版本号。