addLF¶

Appends an LF if a rendered message does not already end with one, ensuring full-line records.

This parameter applies to omfile: File Output Module.

Name:: addLF
Scope:: module, action
Type:: boolean
Default:: module=on; action=inherits module
Required?:: no
Introduced:: 8.2510.0

Description¶

When enabled, the omfile action checks whether a rendered message already ends with an LF (line feed). If not, omfile appends one before writing, so that every record is a complete line regardless of the template used.

In text-based logging, a line feed (LF) marks the end of a record. Without it, the record may appear as an incomplete line when viewed with standard tools such as cat or tail -f. The extra byte is added transparently even when compression or cryptographic providers are active.

If set at the module level, the value becomes the default for all omfile actions that do not explicitly define addLF.

Notes on default behavior¶

Since 8.2510.0, the default has been changed to on. In earlier releases, messages without a trailing LF were written as incomplete lines. With the new default, rsyslog ensures that all records end with a line feed.

This change aligns with common user expectations—especially when writing JSON logs, where line-separated records are the norm. If incomplete lines are desired, you can disable the feature either globally at the module level or for individual actions.

Module usage¶

To override the default globally and allow incomplete lines, disable addLF at the module level:

module(load="builtin:omfile" addLF="off")

Action usage¶

By default, actions inherit the module setting. No explicit parameter is needed:

action(type="omfile" file="/var/log/messages")

In rare cases, you may want to allow incomplete lines only for one action. You can disable addLF explicitly at the action level:

action(type="omfile" file="/var/log/raw.log" addLF="off")

addLF¶

Description¶

Notes on default behavior¶

Module usage¶

Action usage¶

See also¶