Simple non-interactive all-purpose resource fetcher
snarf [-avqprzm] URL [outfile] ...
Retrieves data from a variety of protocols, namely http, ftp, and gopher.
snarf is invoked with any number of URLs and outfiles. If an outfile is not specified, snarf preserves the remote file name when saving.
For example, snarf http://foo.bar.com/images/face.gif will retrieve the file ``face.gif'' to the local system. In the event that there is no filename (the url ends in a slash), the data is retrieved and stored in the file index.html for http URLs, ftpindex.txt for ftp URLs, or gopherindex.txt for gopher URLs.
Using a dash, "-", as the outfile causes snarf to send its output to stdout rather than a file.
To log in to an ftp server or website that requires a username and password, use the syntax http://username:[email protected]/. If you omit the password, you will be prompted for it.
Snarf has a built-in option to download the latest version of itself; simply run snarf LATEST.
-a
Causes snarf to use "active" ftp. By default, snarf uses passive ftp, and, if the server does not support it, falls back to active ftp. Using the -a option will avoid the initial passive attempt.
-r
Resumes an interrupted ftp or http transfer by checking if there is a local file with the same name as the remote file, and starting the transfer at the end of the local file and continuing until finished. This option only works with HTTP servers that understand HTTP/1.1 and ftp servers that support the REST command. snarf uses this option automatically if the outfile already exists.
-n
Don't resume; ignore the outfile if it exists and re-transfer it in its entirety.
-q
Don't print progress bars.
-p
Forces printing of progress bars. Snarf has a compile-time option for whether progress bars print by default or not. The -p option overrides the -q option. In addition, if progress bars are enabled by default, snarf suppresses them when standard output is not a terminal. Using -p will override this behavior.
-v
Prints all messages that come from the server to stderr.
-z
Send a user-agent string similar to what Netscape Navigator 4.0 uses.
-m
Send a user-agent string similar to what Microsoft Internet Explorer uses.
Each option only affects the URL that immediately follows it. To have an option affect all URLs that follow it, use an uppercase letter for the option, e.g. -Q instead of -q.
Snarf checks several environment variables when deciding what to use for a proxy. It checks a service-specific variable first, then SNARF_PROXY, then PROXY.
The service-specific variables are HTTP_PROXY, FTP_PROXY, and GOPHER_PROXY.
Snarf also checks the SNARF_HTTP_USER_AGENT environment variable and will use it when reporting its user-agent string to an HTTP server. In the same spirit, it also uses the SNARF_HTTP_REFERER environment variable to spoof a Referer to the web server.
Bugs? What bugs? If you find 'em, report 'em.
Copyright (C) 2000 Zachary Beane ([email protected])