PAM_MOTD(8)                    Linux-PAM Manual                    PAM_MOTD(8)

NAME
       pam_motd - Display the motd file

SYNOPSIS
       pam_motd.so [motd=/path/filename] [motd_dir=/path/dirname.d]

DESCRIPTION
       pam_motd is a PAM module that can be used to display arbitrary motd
       (message of the day) files after a successful login. By default,
       pam_motd shows files in the following locations:

           /etc/motd
           /run/motd
           /usr/lib/motd
           /etc/motd.d/
           /run/motd.d/
           /usr/lib/motd.d/

       Each message size is limited to 64KB.

       If /etc/motd does not exist, then /run/motd is shown. If /run/motd does
       not exist, then /usr/lib/motd is shown.

       Similar overriding behavior applies to the directories. Files in
       /etc/motd.d/ override files with the same name in /run/motd.d/ and
       /usr/lib/motd.d/. Files in /run/motd.d/ override files with the same
       name in /usr/lib/motd.d/.

       Files in the directories listed above are displayed in lexicographic
       order by name. Moreover, the files are filtered by reading them with
       the credentials of the target user authenticating on the system.

       To silence a message, a symbolic link with target /dev/null may be
       placed in /etc/motd.d with the same filename as the message to be
       silenced. Example: Creating a symbolic link as follows silences
       /usr/lib/motd.d/my_motd.

       ln -s /dev/null /etc/motd.d/my_motd

       The MOTD_SHOWN=pam environment variable is set after showing the motd
       files, even when all of them were silenced using symbolic links.

OPTIONS
       motd=/path/filename
           The /path/filename file is displayed as message of the day.
           Multiple paths to try can be specified as a colon-separated list.
           By default this option is set to /etc/motd:/run/motd:/usr/lib/motd.

       motd_dir=/path/dirname.d
           The /path/dirname.d directory is scanned and each file contained
           inside of it is displayed. Multiple directories to scan can be
           specified as a colon-separated list. By default this option is set
           to /etc/motd.d:/run/motd.d:/usr/lib/motd.d.

       When no options are given, the default behavior applies for both
       options. Specifying either option (or both) will disable the default
       behavior for both options.

MODULE TYPES PROVIDED
       Only the session module type is provided.

RETURN VALUES
       PAM_ABORT
           Not all relevant data or options could be obtained.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_IGNORE
           This is the default return value of this module.

EXAMPLES
       The suggested usage for /etc/pam.d/login is:

           session  optional  pam_motd.so


       To use a motd file from a different location:

           session  optional  pam_motd.so motd=/elsewhere/motd


       To use a motd file from elsewhere, along with a corresponding .d
       directory:

           session  optional  pam_motd.so motd=/elsewhere/motd motd_dir=/elsewhere/motd.d



SEE ALSO
       motd(5), pam.conf(5), pam.d(5), pam(8)

AUTHOR
       pam_motd was written by Ben Collins <bcollins@debian.org>.

       The motd_dir= option was added by Allison Karlitskaya
       <allison.karlitskaya@redhat.com>.

Linux-PAM                         04/09/2024                       PAM_MOTD(8)