shadow/man/pwck.8

.\"$Id: pwck.8,v 1.18 2005/04/12 17:55:55 kloczek Exp $
.\" Copyright 1992, Julianne Frances Haugh
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.TH PWCK 8
.SH NAME
pwck \- verify integrity of password files
.SH SYNOPSIS
\fBpwck\fR [\fB\-sr\fR] [\fIpasswd\fR \fIshadow\fR]
.SH DESCRIPTION
\fBpwck\fR verifies the integrity of the system authentication information.
All entries in the \fI/etc/passwd\fR and \fI/etc/shadow\fR are checked to
see that the entry has the proper format and valid data in each field.
The user is prompted to delete entries that are improperly formatted or
which have other uncorrectable errors.
.P
Checks are made to verify that each entry has
.sp
.in +.5i
\- the correct number of fields
.br
\- a unique user name
.br
\- a valid user and group identifier
.br
\- a valid primary group
.br
\- a valid home directory
.br
\- a valid login shell
.in \-.5i
.sp
.PP
The checks for correct number of fields and unique user name are fatal. If
the entry has the wrong number of fields, the user will be prompted to
delete the entire line. If the user does not answer affirmatively, all
further checks are bypassed. An entry with a duplicated user name is
prompted for deletion, but the remaining checks will still be made. All
other errors are warning and the user is encouraged to run the
\fBusermod\fR command to correct the error.
.PP
The commands which operate on the \fI/etc/passwd\fR file are not able to
alter corrupted or duplicated entries.
\fBpwck\fR should be used in those circumstances to remove the offending
entry.
.SH OPTIONS
By default, \fBpwck\fR operates on the files \fI/etc/passwd\fR and
\fI/etc/shadow\fR. The user may select alternate files with the \fIpasswd\fR
and \fIshadow\fR parameters. Additionally, the user may execute the command
in read\-only mode by specifying the \fB\-r\fR flag. This causes all questions
regarding changes to be answered \fBno\fR without user intervention.
\fBpwck\fR can also sort entries in \fI/etc/passwd\fR and \fI/etc/shadow\fR
by UID. To run it in sort mode pass it \fB\-s\fR flag. No checks are
performed then, it just sorts.
.SH FILES
\fI/etc/passwd\fR	\- user account information
.br
\fI/etc/shadow\fR	\- secure user account information
.br
\fI/etc/group\fR	\- group account information
.SH SEE ALSO
.BR group (5),
.BR passwd (5),
.BR shadow (5),
.BR usermod (8)
.SH EXIT VALUES
.TP 2
The \fBpwck\fR command exits with the following values:
\fB0\fR	\- success
.br
\fB1\fR	\- invalid command syntax
.br
\fB2\fR	\- one or more bad password entries
.br
\fB3\fR	\- can't open password files
.br
\fB4\fR	\- can't lock password files
.br
\fB5\fR	\- can't update password files
.SH AUTHOR
Julianne Frances Haugh (jockgrrl@ix.netcom.com)