htpasswd建立和更新存储用户名、密码的文本文件， 用于对HTTP用户的basic认证。
# /usr/local/apache/bin/htpasswd --help
Usage:
htpasswd [-cmdpsD] passwordfile username
htpasswd -b[cmdpsD] passwordfile username password htpasswd -n[mdps] username
htpasswd -nb[mdps] username password
-c Create a new file.
-n Don't update file; display results on stdout.
-m Force MD5 encryption of the password (default).
-d Force CRYPT encryption of the password.
-p Do not encrypt the password (plaintext).
-s Force SHA encryption of the password.
-b Use the password from the command line rather than prompting for it.
-D Delete the specified user.
On other systems than Windows, NetWare and TPF the '-p' flag will probably not work.
The SHA algorithm does not use a salt and is less secure than the MD5 algorithm.
htpasswd参数
-c 创建passwdfile.如果passwdfile 已经存在,那么它会重新写入并删去原有内容.
-n 不更新passwordfile，直接显示密码
-m 使用MD5加密（默认）
-d 使用CRYPT加密（默认）
-p 使用普通文本格式的密码
-s 使用SHA加密
-b 命令行中一并输入用户名和密码而不是根据提示输入密码，可以看见明文，不需要交互
-D 删除指定的用户
实例
1. 如何利用htpasswd命令添加用户？
# /usr/local/apache/bin/htpasswd -bc linuxeye_pd linuxeye_user linuxeye_password
Adding password for user linuxeye_user
# cat linuxeye_pd
linuxeye_user:$apr1$Mugpp3FE$zGsi7/JfQIhFXPlgqo/Wx/
生成当前目录下生成一个linuxeye_pd文件，用户名linuxeye_user，密码：linuxeye_password，默认采用MD5加密方式
2. 如何在原有密码文件中增加下一个用户？
# /usr/local/apache/bin/htpasswd -b linuxeye_pd linuxeye.com linuxeye.com
Adding password for user linuxeye.com
# cat linuxeye_pd
linuxeye_user:$apr1$Mugpp3FE$zGsi7/JfQIhFXPlgqo/Wx/
linuxeye.com:$apr1$/8EUOPYI$4MBxYpzotrSDcTTDZvTeT0
一定要去掉-c选项，否则覆盖密码文件再创建
3. 如何不更新密码文件，只显示加密后的用户名和密码？
# /usr/local/apache/bin/htpasswd -n linuxeye
New password:
Re-type new password:
linuxeye:$apr1$bZ6Gclc4$zKRap.0BADzZIxLoxpDNv0 # /usr/local/apache/bin/htpasswd -nb linuxeye linuxeye_password
linuxeye:$apr1$yvngdKGV$QrnlriJ.MxIu52Vmo.ROE1
4. 如何利用htpasswd命令删除用户名和密码？
# /usr/local/apache/bin/htpasswd -D linuxeye_pd linuxeye_user
Deleting password for user linuxeye_user
# cat linuxeye_pd
linuxeye.com:$apr1$/8EUOPYI$4MBxYpzotrSDcTTDZvTeT0
5. 如何利用htpasswd命令修改密码？
# /usr/local/apache/bin/htpasswd -D linuxeye_pd linuxeye.com
Deleting password for user linuxeye.com
# /usr/local/apache/bin/htpasswd -b linuxeye_pd linuxeye.com linuxeye_passwd
Adding password for user linuxeye.com
# cat linuxeye_pd
linuxeye.com:$apr1$74ZvB1vC$/b7ETmg8xhDPieYj0b0cE.
需要先利用htpasswd命令删除指定用户，再利用htpasswd添加用户命令创建用户即可实现修改密码的功能。