sdjournal1
Provide an interface to capture systemd journal entries.
Usage
sdjournal [--help]
[--version]
[--extcap-interfaces]
[--extcap-dlts]
[--extcap-interface=<interface>]
[--extcap-config]
[--capture]
[--fifo=<path
to
file
or
pipe>]
[--start-from=<entry
count>]
Overview
sdjournal is an extcap tool that allows one to capture systemd journal entries. It can be used to correlate system events with network traffic.
Supported interfaces:
1. sdjournal
Options
-
--help -
Print program arguments.
-
--version -
Print program version.
-
--extcap-interfaces -
List available interfaces.
-
--extcap-interface=<interface> -
Use specified interfaces.
-
--extcap-dlts -
List DLTs of specified interface.
-
--extcap-config -
List configuration options of specified interface.
-
--capture -
Start capturing from specified interface and write raw packet data to the location specified by --fifo.
--fifo=<path to file or pipe>
Save captured packet to file or send it through pipe.
--start-from=<entry count>
Start from the last <entry count> entries, similar to the "-n" or "--lines" argument for the tail(1) command. Values prefixed with a + sign start from the beginning of the journal, otherwise the count starts from the end. The default value is 10. To include all entries use +0.
Examples
To see program arguments:
sdjournal --help
To see program version:
sdjournal --version
To see interfaces:
sdjournal --extcap-interfaces
Only one interface (sdjournal) is supported.
Example output
interface {value=sdjournal}{display=systemd journal capture}
To see interface DLTs:
sdjournal --extcap-interface=sdjournal --extcap-dlts
Example output
dlt {number=147}{name=sdjournal}{display=USER0}
To see interface configuration options:
sdjournal --extcap-interface=sdjournal --extcap-config
Example output
arg {number=0}{call=--start-from}{display=Starting position}{type=string}
{tooltip=The journal starting position. Values with a leading "+" start from the beginning, similar to the "tail" command}
To capture:
sdjournal --extcap-interface=sdjournal --fifo=/tmp/sdjournal.pcap --capture
To capture all entries since the system was booted:
sdjournal --extcap-interface=sdjournal --fifo=/tmp/sdjournal.pcap --capture --start-from +0
Note
To stop capturing CTRL+C/kill/terminate the application.
Notes
sdjournal is part of the Wireshark distribution. The latest version of Wireshark can be found at <https://www.wireshark.org>.
HTML versions of the Wireshark project man pages are available at <https://www.wireshark.org/docs/man-pages>.
History
- Arch Linux 2026-11-01: the text shown here
- Debian 13 (Trixie)
- Debian 12 (Bookworm)