'\" t .\" Title: shadow .\" Author: Julianne Frances Haugh .\" Generator: DocBook XSL Stylesheets vsnapshot .\" Date: 2022-01-22 .\" Manual: File Formats and Configuration Files .\" Source: shadow-utils 4.11.1 .\" Language: Chinese Simplified .\" .TH "SHADOW" "5" "2022-01-22" "shadow\-utils 4\&.11\&.1" "File Formats and Configuration" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "名称" shadow \- 影子化了的密码文件 .SH "描述" .PP shadow is a file which contains the password information for the system\*(Aqs accounts and optional aging information\&. .PP 如果没有维护好密码安全，此文件绝对不能让普通用户可读。 .PP Each line of this file contains 9 fields, separated by colons (\(lq:\(rq), in the following order: .PP \fB登录名\fR .RS 4 必须是有效的账户名，且已经存在于系统中。 .RE .PP \fB加密了的密码\fR .RS 4 This field may be empty, in which case no passwords are required to authenticate as the specified login name\&. However, some applications which read the /etc/shadow file may decide not to permit any access at all if the password field is empty\&. .sp A password field which starts with an exclamation mark means that the password is locked\&. The remaining characters on the line represent the password field before the password was locked\&. .sp Refer to \fBcrypt\fR(3) for details on how this string is interpreted\&. .sp If the password field contains some string that is not a valid result of \fBcrypt\fR(3), for instance ! or *, the user will not be able to use a unix password to log in (but the user may log in the system by other means)\&. .RE .PP \fB最后一次更改密码的日期\fR .RS 4 The date of the last password change, expressed as the number of days since Jan 1, 1970 00:00 UTC\&. .sp The value 0 has a special meaning, which is that the user should change her password the next time she will log in the system\&. .sp 空字段表示密码年龄功能被禁用。 .RE .PP \fB密码的最小年龄\fR .RS 4 最小密码年龄是指，用户一次更改密码之后，要等多长时间才再次被允许更改密码。 .sp An empty field and value 0 mean that there is no minimum password age\&. .RE .PP \fB最大密码年龄\fR .RS 4 最大密码年龄是指，这写天之后，用户必须更改密码。 .sp 这写天之后，密码仍然可用。用户将会在下次登录的时候被要求更改密码。 .sp 空字段表示没有最大密码年龄，没有密码警告时间段，没有密码禁用时间段(请看下边)。 .sp 如果最大密码年龄小于最小密码年龄，用户将会不能更改密码。 .RE .PP \fB密码警告时间段\fR .RS 4 密码过期之前，提前警告用户的的天数(请参考上边的密码的最大年龄)。 .sp 空字段或者 0 表示没有密码警告期。 .RE .PP \fB密码禁用期\fR .RS 4 密码过期(查看上边的密码最大年龄)后，仍然接受此密码的天数(在此期间，用户应该在下次登录时修改密码)。 .sp After expiration of the password and this expiration period is elapsed, no login is possible for the user\&. The user should contact her administrator\&. .sp 空字段表示没有强制密码过期。 .RE .PP \fB账户过期日期\fR .RS 4 The date of expiration of the account, expressed as the number of days since Jan 1, 1970 00:00 UTC\&. .sp Note that an account expiration differs from a password expiration\&. In case of an account expiration, the user shall not be allowed to login\&. In case of a password expiration, the user is not allowed to login using her password\&. .sp 空字段表示账户永不过期。 .sp 应该避免使用 0，因为它既能理解成永不过期也能理解成在1970年1月1日过期。 .RE .PP \fB保留字段\fR .RS 4 此字段保留作将来使用。 .RE .SH "文件" .PP /etc/passwd .RS 4 用户账户信息。 .RE .PP /etc/shadow .RS 4 安全用户账户信息。 .RE .PP /etc/shadow\- .RS 4 /etc/shadow 的备份文件。 .sp 注意，此文件由 shadow 工具集使用，而不是所有的用户和密码管理工具都会使用。 .RE .SH "参见" .PP \fBchage\fR(1), \fBlogin\fR(1), \fBpasswd\fR(1), \fBpasswd\fR(5), \fBpwck\fR(8), \fBpwconv\fR(8), \fBpwunconv\fR(8), \fBsu\fR(1), \fBsulogin\fR(8)\&.