New script: RFCtool

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Do you find yourself reading a TON of RFCs? I definitely do.

I wrote a tool purely in python 3 that will let you either download all RFCs published, download a specific RFC, OR – and this is the handy thing – view it right in your terminal. No more futzing with lynx or alt-tabbing to a browser.

EDIT: So apparently, and I wish I knew of this beforehand, but there is already a (python-driven) tool for this! It is quite a fair bit more heavy, though it does support more features. It’s simply called ietf and I have packed it in the AUR as ietf-cli. I may include RFCtool as well, simply because it’s better for cron and more lightweight, or I may package it separately.


RFCtool has two modes of invocation: Download(d) or Print/Pager(p).

Each mode has its own separate help, too.

In other words, assuming you copied the script as, you can get usage-specific help for downloading via d -h, whereas you can get help for the printing/paging function with p -h.

The code

#!/usr/bin/env python3

import os
import argparse
import textwrap
import tarfile
import io
import re
import pydoc
from urllib.request import urlopen

# TODO: non-txt format support? (i.e. PDF, HTML, etc.)

def downloadRFC(destdir, rfcnum):
    rfcnum = (str(rfcnum)).lower()  # In case argparse interprets it as an int or it's entered in uppercase
    # For when we implement format support:
    # "plain" = raw text
    # "html" = html text
    # "pdf" = pdf text
    # "x-gzip" is for a gzipped presumably tarball, but we use the "all" keyword for this.
    filetypes = ['plain', 'html', 'pdf', 'x-gzip']
    filext = {}
    for t in filetypes:
        filext[t] = t
    filext['plain'] = 'txt'
    filext['x-gzip'] = 'txt'
    if rfcnum == 'all':
        rfcuri = ''
        rfctype = 'tar'
        filetype = 'x-gzip'
        rfcuri = '{0}.txt'.format(rfcnum)
        rfctype = 'plain'  # We'll make use of this later.
        filetype = 'plain'
    rfcdir = '{0}/{1}'.format(destdir, filext[filetype])
    os.makedirs(rfcdir, exist_ok = True)
    # And some minor fixes. We don't need .txt extension for plaintype. Remove if someone complains.
    if filetype == 'plain':
        rfcpath = '{0}/{1}'.format(rfcdir, rfcnum)
    elif filetype == 'x-gzip':
        # We need to handle this a special way, since it's a gzipped tarball.
       rfcpath = rfcdir
        rfcpath = '{0}/{1}.{2}'.format(rfcdir, rfcnum, filext[filetype])
    with urlopen(rfcuri) as rfc:
        # Is this a single RFC, a release tarball, etc.
        # Commented out for now until we implement multi-format support, as we have the 'all' keyword to help us.
        #rfctype =
        # Handle the tarball here.
        if filetype == 'x-gzip':
            content = io.BytesIO(
            tarball = = content)
            for i in tarball.getnames():
                filedest = '{0}/{1}'.format(rfcpath, re.sub('^rfc([0-9]+)\.txt$', '\g<1>', i))
                if re.match('^rfc[0-9]+\.txt$', i):
                    with tarball.extractfile(i) as e:
                        with open(filedest, 'wb') as f:
        # We don't need to extract from the tarball, so we can just handle it as a plain read.
            content =
            with open(rfcpath, 'wb') as f:

def pageRFC(rfcnum):
    rfcnum = (str(rfcnum)).lower()  # In case argparse interprets it as an int or it's entered in uppercase
    with urlopen('{0}.txt'.format(rfcnum)) as rfc:

def parseArgs():
    args = argparse.ArgumentParser(description = 'RFC Downloader/Viewer',
                                    epilog = 'TIP: this program has context-specific help. e.g. try "%(prog)s d -h"\n')
    subparsers = args.add_subparsers(help = 'Operation to perform', dest = 'operation')
    downloadargs = subparsers.add_parser('d', help = 'Download an RFC/RFCs.')
    pagerargs = subparsers.add_parser('p', help = 'Print the RFC to the terminal.')  # TODO: add -b/--browser? redirect to lynx for html paging?
                        dest = 'destdir',
                        metavar = 'DESTINATION',
                        default = '/usr/local/share/doc/rfc',
                        help = 'The destination directory to save the RFC to. Will be created if it doesn\'t exist (assuming we have permissions). The default is /usr/local/share/doc/rfc/.')
    downloadargs.add_argument(dest = 'rfcnum',
                        metavar = 'RFC',
                        default = 'all',
                        help = 'The RFC number. If the special value "all" is used, then ALL of the published RFCs will be fetched.')
    pagerargs.add_argument(dest = 'rfcnum',
                        metavar = 'RFC',
                        help = 'The RFC number.')

def main():
    argsin = parseArgs()
    args = argsin.parse_args()
    if args.operation == 'd':
        downloadRFC(args.destdir, args.rfcnum)
    elif args.operation == 'p':

if __name__ == '__main__':

As you can see, there are a couple TODOs- mostly feature requests (downloading in PDF or HTML format, or paging to lynx instead for easier browsing). But for now, it’s pretty freaking solid and useful, I’d say.

Categories Python, SysAdmin


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