Make and load backups of R objects

When work with data becomes risky, the best practice is to produce backup files. The function of backup_object is a wrapper of save(), adding a time stamp and a suffix to the name of the resulting file (an R image file with extension *.rda). The function load_last is adapted to this style, loading the newest version to the session.

Usage

backup_object(
  ...,
  objects = character(),
  file,
  stamp = TRUE,
  sep = "_",
  date_format = "%Y-%m-%d",
  time_format = "%H:%M:%S",
  overwrite = FALSE
)

sort_backups(
  name,
  path = ".",
  date_format = "%Y-%m-%d",
  fext = ".rda",
  sep = "_"
)

load_last(file, path, ..., choice)

Arguments

...

Names of the objects to be saved (either symbols or character strings) in backup_object(). In load_last(), arguments passed to sort_backups().

objects

A character vector indicating the names of objects to be included in the backup file.

file

A character value indicating the name of the backup file, without the extension.

stamp

A logical value indicating whether time should be stamped in the backup name or not.

sep

A character value used to separate backup's name from stamp and from the suffix.

date_format

A character value indicating the format used for the file stamp. See strptime().

time_format

A character value indicating the format used for the the time (not including the date), which will be used for the invisible report in backup_object(). See strptime().

overwrite

A logical value indicating whether existing files must be overwritten or not.

name

A character value indicating the root of the backup's name.

path

A character value indicating the path to the folder containing the backup files.

fext

A character value indicating the file extension (including the dot symbol).

choice

An integer value indicating the backup file to be used for recovery. This value refers to the row in the output of sort_backups(). If not provided, load_last() will select the newest backup.

Value

The function backup_object() writes an R-image with extension *.rda and an invisible vector with the name of the backup, its absolute path and a time stamp.

The function sort_backups() returns a data frame including the sorted names of backup files from the oldest to the newest.

Details

In both functions the argument file may include either the path relative to the working directory or the absolute path to the file, excluding stamps and extension. For overwrite=FALSE (the default), a numeric suffix will be added to the backup's name, if another backup was produced at the same day. For overwrite=TRUE no suffix will be included in the file and existing files will be overwritten.

The function load_last() will load the newest version among backups stored in the same folder, provided that the backup name includes a time stamp.

See also

save(), load().

Author

Miguel Alvarez kamapu78@gmail.com

Examples

## A subset with Pseudognaphalium and relatives
Pseudognaphalium <- subset(x = Easplist, subset = grepl("Pseudognaphalium",
        TaxonName), slot = "names", keep_parents = TRUE)

## Create a backup with date stamp in tempdir
backup_object(Pseudognaphalium, file = file.path(tempdir(), "Pseudognaphalium"))
#> Error in save(..., list = objects, file = file.path(path, paste0(file2,     ".rda"))): object ‘Pseudognaphalium’ not found

## Retrieve paths of backup
info_back <- backup_object(Pseudognaphalium, file = file.path(tempdir(),
        "Pseudognaphalium"))
#> Error in save(..., list = objects, file = file.path(path, paste0(file2,     ".rda"))): object ‘Pseudognaphalium’ not found
info_back
#> Error: object 'info_back' not found

## Display all backups
sort_backups("Pseudognaphalium", tempdir())
#> Error in sort_backups("Pseudognaphalium", tempdir()): The requested backup is missing.

## Delete object
rm(list = "Pseudognaphalium")

## To load the last backup into a session
load_last("Pseudognaphalium", path = tempdir())
#> Error in sort_backups(name = file, path = path, ...): The requested backup is missing.

## Load pre-installed backup
load_last(file.path(path.package("taxlist"), "extdata", "Podocarpus"))
#> Loading file 'Podocarpus_2020-01-10.rda' to session.