查版本号的命令
[root@localhost yum.repos.d]# cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)
https://www.cnblogs.com/lfxx/p/17287253.html
1 备份现有的yum源
cd /etc/yum.repos.d/
mkdir bak
mv *.repo /etc/yum.repos.d/bak
2 创建阿里云yum源
方式2：
wget -O /etc/yum.repos.d/aliyun.repo http://mirrors.aliyun.com/repo/Centos-7.repo
3 清理并重新加载yum源
yum clean all && yum makecache
yum install vim
yum install tree
cd /
tree
[root@localhost vmware-tools-distrib]# yum --help
Loaded plugins: fastestmirror, langpacks
Usage: yum [options] COMMAND
List of Commands:
check Check for problems in the rpmdb
check-update Check for available package updates
clean Remove cached data
deplist List a package's dependencies
distribution-synchronization Synchronize installed packages to the latest available versions
downgrade downgrade a package
erase Remove a package or packages from your system
fs Acts on the filesystem data of the host, mainly for removing docs/lanuages for minimal hosts.
fssnapshot Creates filesystem snapshots, or lists/deletes current snapshots.
groups Display, or use, the groups information
help Display a helpful usage message
history Display, or use, the transaction history
info Display details about a package or group of packages
install Install a package or packages on your system
langavailable Check available languages
langinfo List languages information
langinstall Install appropriate language packs for a language
langlist List installed languages
langremove Remove installed language packs for a language
list List a package or groups of packages
load-transaction load a saved transaction from filename
makecache Generate the metadata cache
provides Find what package provides the given value
reinstall reinstall a package
repo-pkgs Treat a repo. as a group of packages, so we can install/remove all of them
repolist Display the configured software repositories
search Search package details for the given string
shell Run an interactive yum shell
swap Simple way to swap packages, instead of using shell
update Update a package or packages on your system
update-minimal Works like upgrade, but goes to the 'newest' package match which fixes a problem that affects your system
updateinfo Acts on repository update information
upgrade Update packages taking obsoletes into account
version Display a version for the machine and/or available repos.
Options:
-h, --help show this help message and exit
-t, --tolerant be tolerant of errors
-C, --cacheonly run entirely from system cache, don't update cache
-c [config file], --config=[config file]
config file location
-R [minutes], --randomwait=[minutes]
maximum command wait time
-d [debug level], --debuglevel=[debug level]
debugging output level
--showduplicates show duplicates, in repos, in list/search commands
-e [error level], --errorlevel=[error level]
error output level
--rpmverbosity=[debug level name]
debugging output level for rpm
-q, --quiet quiet operation
-v, --verbose verbose operation
-y, --assumeyes answer yes for all questions
--assumeno answer no for all questions
--version show Yum version and exit
--installroot=[path] set install root
--enablerepo=[repo] enable one or more repositories (wildcards allowed)
--disablerepo=[repo] disable one or more repositories (wildcards allowed)
-x [package], --exclude=[package]
exclude package(s) by name or glob
--disableexcludes=[repo]
disable exclude from main, for a repo or for
everything
--disableincludes=[repo]
disable includepkgs for a repo or for everything
--obsoletes enable obsoletes processing during updates
--noplugins disable Yum plugins
--nogpgcheck disable gpg signature checking
--disableplugin=[plugin]
disable plugins by name
--enableplugin=[plugin]
enable plugins by name
--skip-broken skip packages with depsolving problems
--color=COLOR control whether color is used
--releasever=RELEASEVER
set value of $releasever in yum config and repo files
--downloadonly don't update, just download
--downloaddir=DLDIR specifies an alternate directory to store packages
--setopt=SETOPTS set arbitrary config and repo options
--bugfix Include bugfix relevant packages, in updates
--security Include security relevant packages, in updates
--advisory=ADVS, --advisories=ADVS
Include packages needed to fix the given advisory, in
updates
--bzs=BZS Include packages needed to fix the given BZ, in
updates
--cves=CVES Include packages needed to fix the given CVE, in
updates
--sec-severity=SEVS, --secseverity=SEVS
Include security relevant packages matching the
severity, in updates
Plugin Options: