openntpd-openbsd/src/lib/libutil/pw_lock.3

.\"	$OpenBSD: pw_lock.3,v 1.9 2002/05/01 08:03:30 mpech Exp $
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.Dd August 20, 2001
.Dt PW_LOCK 3
.Os
.Sh NAME
.Nm pw_lock ,
.Nm pw_mkdb ,
.Nm pw_abort
.Nd passwd file update functions
.Sh SYNOPSIS
.Fd #include <util.h>
.Ft int
.Fn pw_lock "int retries"
.Ft int
.Fn pw_mkdb "char *username" "int pwflags"
.Ft void
.Fn pw_abort
.Sh DESCRIPTION
The
.Fn pw_lock ,
.Fn pw_mkdb ,
and
.Fn pw_abort
functions allow a program to update the system passwd database.
.Pp
The
.Fn pw_lock
function attempts to lock the passwd database by creating the file
.Pa /etc/ptmp
with an exclusive lock (using
.Xr flock 2
semantics) and returns the file descriptor of that file.
If
.Fa retries
is greater than zero,
.Fn pw_lock
will try multiple times to open
.Pa /etc/ptmp ,
waiting one second between tries.
In addition to being a lock file,
.Pa /etc/ptmp
will also hold the contents of the new passwd file.
.Pp
The
.Fn pw_mkdb
function updates the passwd file from the contents of
.Pa /etc/ptmp
via
.Xr pwd_mkdb 8 .
If a
.Fa username
is specified, only the record for the specified user will be updated.
The
.Fa pwflags
are specified by
.Tn OR Ns 'ing
the following values:
.Pp
.Bl -tag -width _PASSWORD_SECUREONLY -offset "xxxx" -compact
.It Dv _PASSWORD_SECUREONLY
only update the secure database file
.Po Pa /etc/spwd.db Pc .
.It Dv _PASSWORD_OMITV7
do not update the Version 7 format password file
.Po Pa /etc/passwd Pc .
.El
.Pp
By default the secure, insecure and Version 7 format password databases
are updated.
You should finish writing to and close the file descriptor returned by
.Fn pw_lock
before calling
.Fn pw_mkdb .
If
.Fn pw_mkdb
fails and you do not wish to retry, you should make sure to call
.Fn pw_abort
to clean up the lock file.
.Pp
The
.Fn pw_abort
function aborts a passwd file update by deleting
.Pa /etc/ptmp .
The passwd database remains unchanged.
.Sh RETURN VALUES
The
.Fn pw_lock
and
.Fn pw_mkdb
functions return \-1 if they are unable to complete properly.
.Sh FILES
.Bl -tag -width /etc/master.passwd -compact
.It Pa /etc/master.passwd
current password file
.It Pa /etc/ptmp
password lock file
.It Pa /etc/passwd
a Version 7 format password file
.It Pa /etc/pwd.db
insecure password database file
.It Pa /etc/spwd.db
secure password database file
.El
.Sh SEE ALSO
.Xr flock 2 ,
.Xr pw_init 3 ,
.Xr pwd_mkdb 8