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My scripts frequently use process substitution for passing script output to syslog:

tag="$(basename "$0")"
exec > >(logger -p local0.info -t "$tag" --id="$$" -e) 2> >(logger -p local0.err -t "$tag" --id="$$" -e)

However, after switching to Ubuntu Jammy these scripts started to produce a weird error:

logger: send message failed: Invalid argument

and the first message from the script does not appear in syslog (subsequent messages do, though).

#!/bin/bash
exec > >(logger -p local0.info --id="$$")
echo "foo"     # 1st message throws error, message not logged
echo "bar"     # subsequent messages logged correctly, no error
echo "baz"

The issue seems to be caused by the parameter --id="$$" in combination with passing messages via STDIN. When passing the message as an argument or omitting the parameter --id="$$" everything works fine.

me@localhost:~ $ echo "foo" | logger -p local0.info --id="$$"  # error, message not logged
logger: send message failed: Invalid argument
me@localhost:~ $ logger -p local0.info --id="$$" "foo"         # no error, message logged
me@localhost:~ $ echo "foo" | logger -p local0.info            # no error, message logged

However, I do want the script PID logged with the message, otherwise distinguishing log messages from different instances of the same script would become a problem. Hence simply omitting --id="$$" is not an option.

This seems to happen only on Ubuntu Jammy, not on older Ubuntu releases (e.g. Xenial) and also not on Devuan.

Addendum:

On Ubuntu the problem seems to occur only in (LXD) containers.

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1 Answer

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This appears to be a recently introduced bug in the logger command. I filed a bug report.

As a workaround you can omit the parameter --id="$$" and instead add the script PID to the tag:

tag="$(basename "$0")[$$]"
exec > >(logger -p local0.info -t "$tag" -e) 2> >(logger -p local0.err -t "$tag" -e)
by (100)
1 7 21
edit history
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