hashUnzip: Extract files from a zip archive downloaded and log checksum...

In PredictiveEcology/webDatabases: Find And Download Canadian Forestry, Ecological And Other Natural Places Data

Description

Unzip dataset previously downloaded from url, first checking if unzip was previously performed (unzip file exists locally).

Usage

hashUnzip(zipfile, destfile, checkhash = TRUE, quick = FALSE,
  dbHash = getOption("webdatabases.dbfile"))

Arguments

zipfile	A character vector. Contains path to zipfile.
destfile	A character string. Represents the name where resulting file is saved.
checkhash	Logical. If TRUE (default), check if file exists locally and cross-check the file's checksum value with that logged from a previous event, skippng redownload if checksum matches. When checksums don't match or file doesn't exist locally, the file is downloaded and its checksum computed. If FALSE, the function is executed even if the file is found locally.
quick	Logical. If TRUE, checksum is compiled using the combination of the filename and its size. If FALSE (default), cheksum is compiled using the object.
dbHash	Character string. The path to the database file where checksum value of file is logged. If the database does not yet exist, one is created. Default is to use the option webdatabases.dbfile.

Value

Invoked for its side-effect of saving unzipped file in a subdirectory using the zipfile basename in the ‘destfile/’ directory.

Author(s)

Melina Houle

Examples

u <-"http://ftp.geogratis.gc.ca/pub/nrcan_rncan/archive/vector/cli_itc_50k/land_use/L040J03.zip"
hashDownload(u, destfile = tempdir(), checkhash= FALSE, cascade = FALSE)
zip <- file.path(tempdir(), basename(u))
hashUnzip(zip, tempdir(), checkhash = FALSE)

PredictiveEcology/webDatabases documentation built on May 8, 2019, 3:09 p.m.