Sysbox: sendlog

Sysbox: sendlog

Usage: sendlog [OPTION]... LONGMESSAGE
or: sendlog -e [OPTION]... [LABEL] MESSAGE

Send a log message to the syslog service. The LABEL and the MESSAGE can be at most 4 or 8 characters (over this length, other character will not be sent). However, LONGMESSAGE can have any length up to 65535.

The -e option means send an emergency message. This will limit the usable number of characters, but the mechanism is faster and even more fail-safe. Actually, it is a simple SendMsg() system call -- not too much can break. The limit above came from the parameters of the SendMsg() system call: there are two free parameters in this call. Always refer to sendlog --help to see the actual limit.

In case of sendlog -e MESSAGE the MESSAGE parameter can be at most 8 (on 32-bit systems) or 16 (on 64-bit systems) characters.

In case of sendlog -e LABEL MESSAGE both the LABEL and the MESSAGE parameter can be at most 4 (on 32-bit systems) or 8 (on 64-bit systems) characters. Between the LABEL and the MESSAGE the syslog service will insert two characters: a colon and a space.

The log messages sent to the syslog service can be read with the readlog tool.



$ sendlog "Hello World! This is an example log message."
$ sendlog -e Hello World
$ sendlog -e Hello_12345678 World_123456789
$ sendlog -e emergency_msg
$ readlog -s 180
[     3028.220] Hello World! This is an example log message.
[     3068.571] Hello   : World   
[     3126.828] Hello_12: World_12
[     3439.792] emergency_msg