download.file {base} | R Documentation |
This function can be used to download a file from the Internet.
download.file(url, destfile, method, quiet = FALSE, mode="w")
url |
A character string with the URL of a resource to be downloaded. |
destfile |
A character string with the name where the downloaded
file is saved. For the "internal" method tilde-expansion is
performed. |
method |
Method to be used for downloading files. Currently
download methods "internal" , "wget" , "lynx"
and "socket" are available. The default is to choose the
first of these which is available, on almost all systems
"internal" . |
quiet |
If TRUE , suppress status messages (if any). |
mode |
character. The mode with which to write the file. Useful
values are "w" , "wb" (binary), "a" (append) and
"ab" . Only used for the "internal" method. |
The function download.file
can be used to download a single
file as described by url
from the internet and store it in
destfile
.
The url
must start with a scheme such as
"http://"
, "ftp://"
or "file://"
.
The remaining details apply to method "internal"
only.
The timeout for many parts of the transder can be set by the option
timeout
which defaults to 60 seconds.
The level of detail provided during transfer can be set by the
quiet
argument and the internet.info
option. The
details depend on the platform and scheme, but setting
internet.info
to 0 gives all available details, including
all server responses. Using 2 (the default) gives only serious
messages, and 3 or more suppresses all messages.
Proxies can be specified via environment variables.
Setting "no_proxy"
stops any proxy being tried.
Otherwise the setting of "http_proxy"
or "ftp_proxy"
(or failing that, the all upper-case version) is consulted and if
non-empty used as a proxy site. For FTP transfers, the username
and password on the proxy can be specified by "ftp_proxy_user"
and "ftp_proxy_password"
.
Methods "wget"
, "lynx"
and "socket"
are for
historical compatibility. They will block any other activity on the
R process.
For methods "wget"
and "lynx"
a system call is made to
the tool given by method
, and the respective program must be
installed on your system and be in the search path for executables.
Method "socket"
is deprecated. To use it the file must be on
an HTTP
server, in plain text, and your system must allow
socket connections to be opened directly to that server (and not
via a proxy or firewall).
options
to set the timeout
and
internet.info
options.
url
for a finer-grained way to read data from URLs.
url.show
, CRAN.packages
,
download.packages
for applications