有时候，我们只知道某个命令的名称，但是不知道这个命令属于哪个工具包。
如果我们要查找某个命令属于哪个工具包，可使用如下命令：

yum provides [command]

例如，我们要查找 htpasswd 这个命令所属的安装包：

[root@versatile ~]# yum provides htpasswd
Loaded plugins: fastestmirror, product-id, search-disabled-repos, subscription-manager

This system is not registered with an entitlement server. You can use subscription-manager to register.

Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast
Determining fastest mirrors
httpd-tools-2.4.6-93.el7.centos.x86_64 : Tools for use with the Apache HTTP Server
Repo        : base
Matched from:
Filename    : /usr/bin/htpasswd


httpd-tools-2.4.6-95.el7.centos.x86_64 : Tools for use with the Apache HTTP Server
Repo        : base
Matched from:
Filename    : /usr/bin/htpasswd


httpd-tools-2.4.6-97.el7.centos.x86_64 : Tools for use with the Apache HTTP Server
Repo        : updates
Matched from:
Filename    : /usr/bin/htpasswd


httpd-tools-2.4.6-97.el7.centos.1.x86_64 : Tools for use with the Apache HTTP Server
Repo        : updates
Matched from:
Filename    : /usr/bin/htpasswd


httpd-tools-2.4.6-97.el7.centos.2.x86_64 : Tools for use with the Apache HTTP Server
Repo        : updates
Matched from:
Filename    : /usr/bin/htpasswd


httpd-tools-2.4.6-97.el7.centos.2.x86_64 : Tools for use with the Apache HTTP Server
Repo        : @updates
Matched from:
Filename    : /usr/bin/htpasswd

根据上面结果，知道了 htpasswd 属于httpd-tools这个安装包，接下来安装即可：

yum install httpd-tools -y