URLGRABBER(1)URLGRABBER(1)NAMEurlgrabber - a high-level cross-protocol url-grabber.
SYNOPSISurlgrabber [OPTIONS] URL [FILE]
DESCRIPTIONurlgrabber is a binary program and python module for fetching files. It
is designed to be used in programs that need common (but not
necessarily simple) url-fetching features.
OPTIONS--help, -h
help page specifying available options to the binary program.
--copy-local
ignored except for file:// urls, in which case it specifies whether
urlgrab should still make a copy of the file, or simply point to
the existing copy.
--throttle=NUMBER
if it's an int, it's the bytes/second throttle limit. If it's a
float, it is first multiplied by bandwidth. If throttle == 0,
throttling is disabled. If None, the module-level default (which
can be set with set_throttle) is used.
--bandwidth=NUMBER
the nominal max bandwidth in bytes/second. If throttle is a float
and bandwidth == 0, throttling is disabled. If None, the
module-level default (which can be set with set_bandwidth) is used.
--range=RANGE
a tuple of the form first_byte,last_byte describing a byte range to
retrieve. Either or both of the values may be specified. If
first_byte is None, byte offset 0 is assumed. If last_byte is None,
the last byte available is assumed. Note that both first and
last_byte values are inclusive so a range of (10,11) would return
the 10th and 11th bytes of the resource.
--user-agent=STR
the user-agent string provide if the url is HTTP.
--retry=NUMBER
the number of times to retry the grab before bailing. If this is
zero, it will retry forever. This was intentional... really, it was
:). If this value is not supplied or is supplied but is None
retrying does not occur.
--retrycodes
a sequence of errorcodes (values of e.errno) for which it should
retry. See the doc on URLGrabError for more details on this.
retrycodes defaults to -1,2,4,5,6,7 if not specified explicitly.
MODULE USE EXAMPLES
In its simplest form, urlgrabber can be a replacement for urllib2's
open, or even python's file if you're just reading:
from urlgrabber import urlopen
fo = urlopen(url)
data = fo.read()fo.close()
Here, the url can be http, https, ftp, or file. It's also pretty smart
so if you just give it something like /tmp/foo, it will figure it out.
For even more fun, you can also do:
from urlgrabber import urlopen
local_filename = urlgrab(url) # grab a local copy of the file
data = urlread(url) # just read the data into a string
Now, like urllib2, what's really happening here is that you're using a
module-level object (called a grabber) that kind of serves as a
default. That's just fine, but you might want to get your own private
version for a couple of reasons:
* it's a little ugly to modify the default grabber because you have to
reach into the module to do it
* you could run into conflicts if different parts of the code
modify the default grabber and therefore expect different
behavior
Therefore, you're probably better off making your own. This also gives
you lots of flexibility for later, as you'll see:
from urlgrabber.grabber import URLGrabber
g = URLGrabber()
data = g.urlread(url)
This is nice because you can specify options when you create the
grabber. For example, let's turn on simple reget mode so that if we
have part of a file, we only need to fetch the rest:
from urlgrabber.grabber import URLGrabber
g = URLGrabber(reget='simple')
local_filename = g.urlgrab(url)
The available options are listed in the module documentation, and can
usually be specified as a default at the grabber-level or as options to
the method:
from urlgrabber.grabber import URLGrabber
g = URLGrabber(reget='simple')
local_filename = g.urlgrab(url, filename=None, reget=None)
AUTHORS
Written by: Michael D. Stenner <mstenner@linux.duke.edu> Ryan Tomayko
<rtomayko@naeblis.cx>
This manual page was written by Kevin Coyner <kevin@rustybear.com> for
the Debian system (but may be used by others). It borrows heavily on
the documentation included in the urlgrabber module. Permission is
granted to copy, distribute and/or modify this document under the terms
of the GNU General Public License, Version 2 any later version
published by the Free Software Foundation.
RESOURCES
Main web site: http://linux.duke.edu/projects/urlgrabber/
04/09/2007 URLGRABBER(1)
