noarch（Linux命令自动补全工具）

什么是命令自动补全

在 Linux 命令行中，当输入字符后，按Tab 键，Shell 就会列出以这些字符开头的所有可用命令，如果只有一个命令匹配到，按一次 Tab 键就自动将这个命令补全。

如果输入pass，此时按 Tab 键，因为以pass开头的命令只有passwd这个命令， Shell 就会自动补全 passwd 命令。

另外如果输入的字符匹配多个命令则会列出所有可用的命令，比如，如果输入do，此时按 Tab 键 Shell 就会自列出可用的命令。

[root@node2 ~]# do

do docker-containerd-shim dockerd done

docker docker-containerd-shim-current dockerd-current

docker-containerd docker-ctr-current docker-storage-setup

docker-containerd-current docker-current domainname

但是系统自带的命令补全功能有限，自动补全功能仅限于命令和文件名。

可以安装 Bash 命令补全增强软件包 bash-completion来实现更多命令的补全。

bash-completion的安装

以centos为例

[root@node1 ~]# cat /etc/redhat-Release

CentOS Linux release 7.7.1908 (Core)

直接通过yum命令安装

yum install bash-completion

bash-completion版本信息

[root@node1 completions]# rpm -qi bash-completion

Name : bash-completion

Epoch : 1

Version : 2.1

Release : 6.el7

Architecture: noarch

Install Date: Thu 19 Mar 2020 07:59:19 AM CST

Group : Unspecified

Size : 264934

License : GPLv2+

Signature : RSA/SHA256, Fri 04 Jul 2014 08:47:01 AM CST, Key ID 24c6a8a7f4a80eb5

Source RPM : bash-completion-2.1-6.el7.src.rpm

Build Date : Tue 10 Jun 2014 08:05:27 AM CST

Build Host : worker1.bsys.centos.org

Relocations : (not relocatable)

Packager : CentOS BuildSystem <http://bugs.centos.org>

Vendor : CentOS

URL : http://bash-completion.alioth.debian.org/

Summary : Programmable completion for Bash

Description :

bash-completion is a collection of shell functions that take advantage

of the programmable completion feature of bash.

配置命令补全

source /usr/share/bash-completion/bash_completion

命令补全的脚本存放在/usr/share/bash-completion/completions/目录，可以在这个目录查看支持增强补全功能的命令。

再试试输入docker命令后按tab键：

[root@node1 completions]# docker

build diff history inspect logs port restart search stats top wait

commit events image kill network ps rm secret stop unpause

container exec images load node pull rmi service swarm update

cp export import login pause push run stack system version

create help info logout plugin rename save start tag volume

[root@node1 completions]# docker

可以看到后续可用命令的提示，妈妈再也不用担心我记不住命令了。

同样对于kubenetes也可以实现命令的自动补全和提示：

[root@node1 ~]# kubectl

annotate certificate cordon drain get port-forward run uncordon

api-versions cluster-info cp edit label proxy scale version

apply completion create exec logs replace set

attach config delete explain options rolling-update taint

autoscale convert describe expose patch rollout top

[root@node1 ~]# kubectl

git的命令补全

如果是在安装bash-completion之后安装git是不能自动命令补全，需要手动进行一些配置。

git安装之后文档里会有git-completion.bash文件

[root@node1 bash-completion]# find / -name git-completion*

/usr/share/doc/git-1.8.3.1/contrib/completion/git-completion.bash

/usr/share/doc/git-1.8.3.1/contrib/completion/git-completion.tcsh

/usr/share/doc/git-1.8.3.1/contrib/completion/git-completion.zsh

/usr/share/bash-completion/completions/git-completion.bash

/usr/share/git-core/contrib/completion/git-completion.tcsh

[root@node1 bash-completion]#

安装完git之后重新source一下bash-completion

source /usr/share/bash-completion/bash_completion

看看配置之后的效果

[root@node3 ~]# git

add cherry difftool init reflog show

am cherry-pick fetch log relink show-branch

annotate clean filter-branch merge remote stage

apply clone format-patch mergetool repack stash

archive column fsck mv replace status

bisect commit gc name-rev request-pull submodule

blame config get-tar-commit-id notes reset subtree

branch credential grep pull revert tag

bundle describe help push rm whatchanged

checkout diff imap-send rebase shortlog

[root@node3 ~]# git

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