'\" t
.\"     Title: passwd
.\"    Author: Julianne Frances Haugh
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 07/02/2024
.\"    Manual: File Formats and Configuration Files
.\"    Source: shadow-utils 4.16.0
.\"  Language: English
.\"
.TH "PASSWD" "5" "07/02/2024" "shadow\-utils 4\&.16\&.0" "File Formats and Configuration"
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.SH "NAME"
passwd \- the password file
.SH "DESCRIPTION"
.PP
/etc/passwd
contains one line for each user account, with seven fields delimited by colons (\(lq:\(rq)\&. These fields are:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
login name
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
optional encrypted password
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
numerical user ID
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
numerical group ID
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
user name or comment field
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
user home directory
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
optional user command interpreter
.RE
.PP
If the
\fIpassword\fR
field is a lower\-case
\(lqx\(rq, then the encrypted password is actually stored in the
\fBshadow\fR(5)
file instead; there
\fImust\fR
be a corresponding line in the
/etc/shadow
file, or else the user account is invalid\&.
.PP
The encrypted
\fIpassword\fR
field may be empty, in which case no password is required to authenticate as the specified login name\&. However, some applications which read the
/etc/passwd
file may decide not to permit
\fIany\fR
access at all if the
\fIpassword\fR
field is blank\&.
.PP
A
\fIpassword\fR
field which starts with an exclamation mark means that the password is locked\&. The remaining characters on the line represent the
\fIpassword\fR
field before the password was locked\&.
.PP
Refer to
\fBcrypt\fR(3)
for details on how this string is interpreted\&.
.PP
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)\&.
.PP
The comment field, also known as the gecos field, is used by various system utilities, such as
\fBfinger\fR(1)\&. The use of an ampersand here will be replaced by the capitalised login name when the field is used or displayed by such system utilities\&.
.PP
The home directory field provides the name of the initial working directory\&. The
\fBlogin\fR
program uses this information to set the value of the
\fB$HOME\fR
environmental variable\&.
.PP
The command interpreter field provides the name of the user\*(Aqs command language interpreter, or the name of the initial program to execute\&. The
\fBlogin\fR
program uses this information to set the value of the
\fB$SHELL\fR
environmental variable\&. If this field is empty, it defaults to the value
/bin/sh\&.
.SH "FILES"
.PP
/etc/passwd
.RS 4
User account information\&.
.RE
.PP
/etc/shadow
.RS 4
optional encrypted password file
.RE
.PP
/etc/passwd\-
.RS 4
Backup file for /etc/passwd\&.
.sp
Note that this file is used by the tools of the shadow toolsuite, but not by all user and password management tools\&.
.RE
.SH "SEE ALSO"
.PP
\fBcrypt\fR(3),
\fBgetent\fR(1),
\fBgetpwnam\fR(3),
\fBlogin\fR(1),
\fBpasswd\fR(1),
\fBpwck\fR(8),
\fBpwconv\fR(8),
\fBpwunconv\fR(8),
\fBshadow\fR(5),
\fBsu\fR(1),
\fBsulogin\fR(8)\&.