/media/bill/PROJECTS/System_maintenance/Linux/journalctl notes.txt
www.BillHowwell.ca  30Aug2018 initial


       journalctl - Query the systemd journal

SYNOPSIS
       journalctl [OPTIONS...] [MATCHES...]

DESCRIPTION
       journalctl may be used to query the contents of the systemd(1) journal as written by systemd-
       journald.service(8).

       If called without parameters, it will show the full contents of the journal, starting with the oldest entry
       collected.

       If one or more match arguments are passed, the output is filtered accordingly. A match is in the format
       "FIELD=VALUE", e.g.  "_SYSTEMD_UNIT=httpd.service", referring to the components of a structured journal
       entry. See systemd.journal-fields(7) for a list of well-known fields. If multiple matches are specified
       matching different fields, the log entries are filtered by both, i.e. the resulting output will show only
       entries matching all the specified matches of this kind. If two matches apply to the same field, then they
       are automatically matched as alternatives, i.e. the resulting output will show entries matching any of the
       specified matches for the same field. Finally, if the character "+" appears as a separate word on the
       command line, all matches before and after are combined in a disjunction (i.e. logical OR).

       As shortcuts for a few types of field/value matches, file paths may be specified. If a file path refers to
       an executable file, this is equivalent to an "_EXE=" match for the canonicalized binary path. Similarly, if
       a path refers to a device node, this is equivalent to a "_KERNEL_DEVICE=" match for the device.

       Output is interleaved from all accessible journal files, whether they are rotated or currently being
       written, and regardless of whether they belong to the system itself or are accessible user journals.

       All users are granted access to their private per-user journals. However, by default, only root and users
       who are members of the "systemd-journal" group get access to the system journal and the journals of other
       users.

       The output is paged through less by default, and long lines are "truncated" to screen width. The hidden
       part can be viewed by using the left-arrow and right-arrow keys. Paging can be disabled; see the --no-pager
       option and the "Environment" section below.

       When outputing to a tty, lines are colored according to priority: lines of level ERROR and higher are
       colored red; lines of level NOTICE and higher are highlighted; other lines are displayed normally.

OPTIONS
       The following options are understood:




*******************
30Aug2018 

$ journalctl
No journal files were found.

$ sudo journalctl
[sudo] password for bill: 
No journal files were found.





# enddoc