PAM_MOTD(8) Linux-PAM Manual PAM_MOTD(8)
pam_motd - Display the motd file
pam_motd.so [motd=/path/filename] [motd_dir=/path/dirname.d]
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.
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.
Only the session module type is provided.
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.
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
motd(5), pam.conf(5), pam.d(5), pam(8)
pam_motd was written by Ben Collins <email@example.com>. The motd_dir= option was added by Allison Karlitskaya <firstname.lastname@example.org>.
This page is part of the linux-pam (Pluggable Authentication Modules for Linux) project. Information about the project can be found at ⟨http://www.linux-pam.org/⟩. If you have a bug report for this manual page, see ⟨//www.linux-pam.org/⟩. This page was obtained from the project's upstream Git repository ⟨https://github.com/linux-pam/linux-pam.git⟩ on 2023-06-23. (At that time, the date of the most recent commit that was found in the repository was 2023-06-07.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to email@example.com Linux-PAM Manual 12/16/2022 PAM_MOTD(8)
Pages that refer to this page: login(1), systemd.system-credentials(7)