---

output: github_document

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.path = "man/figures/README-",
  out.width = "100%"
)
library(rsyslog)

rsyslog

rsyslog is a very simple R package to interface with syslog –
a system logging interface available on all POSIX-compatible operating systems.

Installation

To get the latest stable version from CRAN:

install.packages("rsyslog")

If you need access to in-development features, you can install the package
directly from GitHub:

# install.packages("devtools")
devtools::install_github("atheriel/rsyslog")

Usage

Using rsyslog closely resembles using the syslog
API, so it should be
familiar if you have previous experience with syslog.

Messages are sent to the system log with the syslog() function. You can also
(optionally) configure how messages are written with open_syslog() and close
any open connection with close_syslog().

open_syslog("my_script")
syslog("Running script.", level = "INFO")
syslog("Possible issue.", level = "WARNING")
close_syslog()

To see what this has printed to the system log on systemd-based Linux
distributions (including Ubuntu), you can use the journalctl program:

$ journalctl --identifier my_script

-- Logs begin at Mon 2018-06-25 14:48:12 UTC, end at Mon 2018-06-25 15:35:02 UTC. --
Jun 25 15:10:18 user my_script[4467]: Running script.
Jun 25 15:10:18 user my_script[4467]: Possible issue.

Opening and closing the system log is not strictly necessary (though it is good
practice). The following will work as well:

# Uses the process name (likely "R" or "rsession") as the identifier.
syslog("Hello from R!", level = "WARNING")

If you wish to control the visibility of messages by priority level (for
example, to hide debug messages), use set_syslog_mask():

open_syslog("my_script")
syslog("This message is visible.", level = "INFO")
set_syslog_mask("WARNING")
syslog("No longer visible.", level = "INFO")
syslog("Still visible.", level = "WARNING")
close_syslog()

License

The package is licensed under the GPL, version 2 or later.