R.utils (version 2.9.0)

pushBackupFile: Appends a backup suffix to the pathname

Description

Appends a backup suffix to the pathname and, optionally, renames an existing file accordingly.

In combination with popBackupFile(), this method is useful for creating a backup of a file and restoring it.

Usage

# S3 method for default
pushBackupFile(filename, path=NULL, suffix=".bak", isFile=TRUE,
  onMissing=c("ignore", "error"), copy=FALSE, overwrite=TRUE, ..., verbose=FALSE)

Arguments

filename

The filename of the file to backup.

path

The path of the file.

suffix

The suffix to be appended.

isFile

If TRUE, the file must exist and will be renamed on the file system. If FALSE, it is only the pathname string that will be modified. For details, see below.

onMissing

A character string specifying what to do if the file does not exist.

copy

If TRUE, an existing original file remains after creating the backup copy, otherwise it is dropped.

overwrite

If TRUE, any existing backup files are overwritten, otherwise an exception is thrown.

...

Not used.

verbose

A logical or Verbose.

Value

Returns the pathname with the suffix appended.

See Also

popBackupFile().

Examples

# NOT RUN {
# Create a file
pathname <- file.path(tempdir(), "foobar.txt")
cat(file=pathname, "File v1\n")


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# (a) Backup and restore a file
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Turn it into a backup file
pathnameB <- pushBackupFile(pathname, verbose=TRUE)
print(pathnameB)

# Restore main file from backup
pathnameR <- popBackupFile(pathnameB, verbose=TRUE)
print(pathnameR)


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# (b) Backup, create a new file and frop backup file
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Turn it into a backup file
pathnameB <- pushBackupFile(pathname, verbose=TRUE)
print(pathnameB)

# Create a new file
cat(file=pathname, "File v2\n")

# Drop backup because a new main file was successfully created
pathnameR <- popBackupFile(pathnameB, verbose=TRUE)
print(pathnameR)

# }