shadow/man/chpasswd.8

.\"     Title: chpasswd
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/>
.\"      Date: 07/30/2006
.\"    Manual: System Management Commands
.\"    Source: System Management Commands
.\"
.TH "CHPASSWD" "8" "07/30/2006" "System Management Commands" "System Management Commands"
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.SH "NAME"
chpasswd \- update passwords in batch mode
.SH "SYNOPSIS"
.HP 9
\fBchpasswd\fR [\fIoptions\fR]
.SH "DESCRIPTION"
.PP

\fBchpasswd\fR
reads a list of user name and password pairs from standard input and uses this information to update a group of existing users. Each line is of the format:
.PP

\fIuser_name\fR:\fIpassword\fR
.PP
By default the supplied password must be in clear\-text. Default encryption algorithm is DES. Also the password age will be updated, if present.
.PP
This command is intended to be used in a large system environment where many accounts are created at a single time.
.SH "OPTIONS"
.PP
The options which apply to the
\fBchpasswd\fR
command are:
.TP 3n
\fB\-e\fR, \fB\-\-encrypted\fR
Supplied passwords are in encrypted form.
.TP 3n
\fB\-h\fR, \fB\-\-help\fR
Display help message and exit.
.TP 3n
\fB\-m\fR, \fB\-\-md5\fR
Use MD5 encryption instead of DES when the supplied passwords are not encrypted.
.SH "CAVEATS"
.PP
Remember to set permissions or umask to prevent readability of unencrypted files by other users.
.SH "SEE ALSO"
.PP

\fBpasswd\fR(1),
\fBnewusers\fR(8),
\fBuseradd\fR(8).