1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
require 'open-uri'
class Downloader
def self.mode_for(data)
data.start_with?("#!") ? 0755 : 0644
end
def self.http_options(file, since)
options = {}
if since
case since
when true
since = (File.mtime(file).httpdate rescue nil)
when Time
since = since.httpdate
end
if since
options['If-Modified-Since'] = since
end
end
options
end
# Downloader.download(url, name, [dir, [ims]])
#
# Update a file from url if newer version is available.
# Creates the file if the file doesn't yet exist; however, the
# directory where the file is being created has to exist already.
# If +ims+ is false, already download url regardless its last
# modified time.
#
# Example usage:
# download 'http://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt',
# 'enc/unicode/data/UnicodeData.txt'
def self.download(url, name, dir = nil, ims = true)
file = dir ? File.join(dir, name) : name
url = URI(url)
begin
data = url.read(http_options(file, ims))
rescue OpenURI::HTTPError => http_error
return http_error.message =~ /^304 / # 304 Not Modified
raise
end
mtime = nil
open(file, "wb", 0600) do |f|
f.write(data)
f.chmod(mode_for(data))
mtime = data.meta["last-modified"]
end
if mtime
mtime = Time.httpdate(mtime)
File.utime(mtime, mtime, file)
end
true
rescue => e
raise "failed to download #{name}\n#{e.message}: #{url}"
end
def self.download_if_modified_since(url, name, dir = nil)
download(url, name, dir)
end
end
|
