A function to initialize the log file.
log_open(file_name = "", logdir = TRUE, show_notes = TRUE, autolog = NULL)
The name of the log file. If no path is specified, the working directory will be used.
Send the log to a log directory named "log". If the log directory does not exist, the function will create it. Valid values are TRUE and FALSE. The default is TRUE.
If true, will write notes to the log. Valid values are TRUE and FALSE. Default is TRUE.
Whether to turn on autolog functionality. Autolog automatically logs functions from the dplyr, tidyr, and sassy family of packages. To enable autolog, either set this parameter to TRUE or set the "logr.autolog" option to TRUE. A FALSE value on this parameter will override the global option. The global option will override a NULL on this parameter. Default is that autolog is disabled.
The path of the log.
log_open function initializes and opens the log file.
This function must be called first, before any logging can occur.
The function determines the log path, attaches event handlers,
clears existing log files, and initiates a new log.
file_name parameter may be a full path, a relative path, or
a file name. An relative path or file name will be assumed to be relative
to the current working directory. If the
not have a '.log' extension, the
log_open function will add it.
If requested in the
logdir parameter, the
function will write to a 'log' subdirectory of the path specified in the
file_name. If the 'log' subdirectory does not exist,
the function will create it.
The log file will be initialized with a header that shows the log file name,
the current working directory, the current user, and a timestamp of
log_open function was called.
All errors, the last warning, and any
log_print output will be
written to the log. The log file will exist in the location specified in the
file_name parameter, and will normally have a '.log' extension.
If errors or warnings are generated, a second file will be written that contains only error and warning messages. This second file will have a '.msg' extension and will exist in the specified log directory. If the log is clean, the msg file will not be created. The purpose of the msg file is to give the user a visual indicator from the file system that an error or warning occurred. This indicator msg file is useful when running programs in batch.
To use logr, call
log_open, and then make calls to
log_print as needed to print variables or data frames to the log.
log_print function can be used in place of a standard
be printed to the log, and to the console if working interactively.
This package provides the functionality of
sink, but in much more
user-friendly way. Recommended usage is to call
log_open at the top
of the script, call
log_print as needed to log interim state,
log_close at the bottom of the script.
Logging may be controlled globally using the "logr.on" option. This option
accepts a TRUE or FALSE value. If the option is set to FALSE, logr
will print to the console, but not to the log.
options("logr.on" = TRUE)
Notes may be controlled globally using the "logr.notes" option. This option
also accepts a TRUE or FALSE value, and determines whether or not to print
notes in the log. The global option will override the
parameter on the
options("logr.notes" = FALSE)
Version v1.2.0 of the logr package introduced autolog.
The autolog feature provides automatic logging for dplyr,
tidyr, and the sassy family of packages. To use autolog,
autolog parameter to TRUE, or set the global option
logr.autolog to TRUE. To maintain backward compatibility with
prior versions, autolog is disabled by default.
# Create temp file location tmp <- file.path(tempdir(), "test.log") # Open log lf <- log_open(tmp) # Send message to log log_print("High Mileage Cars Subset") # Perform operations hmc <- subset(mtcars, mtcars$mpg > 20) # Print data to log log_print(hmc) # Close log log_close() # View results writeLines(readLines(lf))