Home • Explore • Blog • CI
☰



man-pages
31th chunk of `systemctl.man`
9654c08120882525dc439f0e490d4171c951a45b355638090000000100000867
 neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known pager implementations are tried in turn, including less(1) and more(1), until one is
           found. If no pager implementation is discovered no pager is invoked. Setting this environment variable to an empty string or the value "cat" is equivalent to passing --no-pager.

           Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER (as well as $PAGER) will be silently ignored.

       $SYSTEMD_LESS
           Override the options passed to less (by default "FRSXMK").

           Users might want to change two options in particular:

           K
               This option instructs the pager to exit immediately when Ctrl+C is pressed. To allow less to handle Ctrl+C itself to switch back to the pager command prompt, unset this option.

               If the value of $SYSTEMD_LESS does not include "K", and the pager that is invoked is less, Ctrl+C will be ignored by the executable, and needs to be handled by the pager.

           X
               This option instructs the pager to not send termcap initialization and deinitialization strings to the terminal. It is set by default to allow command output to remain visible in the terminal even after the
               pager exits. Nevertheless, this prevents some pager functionality from working, in particular paged output cannot be scrolled with the mouse.

           See less(1) for more discussion.

       $SYSTEMD_LESSCHARSET
           Override the charset passed to less (by default "utf-8", if the invoking terminal is determined to be UTF-8 compatible).

       $SYSTEMD_PAGERSECURE
           Takes a boolean argument. When true, the "secure" mode of the pager is enabled; if false, disabled. If $SYSTEMD_PAGERSECURE is not set at all, secure mode is enabled if the effective UID is not the same as the
           owner of the login session, see geteuid(2) and sd_pid_get_owner_uid(3). In secure mode, LESSSECURE=1 will be set when invoking the pager, and the pager shall disable commands that open or create new files or start
           new subprocesses. When $SYSTEMD_PAGERSECURE is not set at all,
Title: More Systemd Environment Variables: Pager Configuration and Security
Summary
This section details more systemd environment variables. It elaborates on `$SYSTEMD_PAGER`, describing the fallback pager selection and the effect of setting it to 'cat'. It then covers `$SYSTEMD_LESS`, explaining how to override `less` options, specifically 'K' (Ctrl+C behavior) and 'X' (termcap strings). `$SYSTEMD_LESSCHARSET` allows overriding the charset passed to less. Finally, `$SYSTEMD_PAGERSECURE` controls the pager's secure mode, which restricts file access and subprocess creation based on UID comparison and sets `LESSSECURE=1`.