adding rfc.py

ref/rfc.py

@@ -0,0 +1,102 @@
+#!/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 = 'https://www.rfc-editor.org/rfc/tar/RFC-all.tar.gz'
+        rfctype = 'tar'
+        filetype = 'x-gzip'
+    else:
+        rfcuri = 'https://tools.ietf.org/rfc/rfc{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
+    else:
+        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 = rfc.response.info().get_content_subtype()
+        # Handle the tarball here.
+        if filetype == 'x-gzip':
+            content = io.BytesIO(rfc.read())
+            tarball = tarfile.open(fileobj = 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:
+                            f.write(e.read())
+        # We don't need to extract from the tarball, so we can just handle it as a plain read.
+        else:
+            content = rfc.read()
+            with open(rfcpath, 'wb') as f:
+                f.write(content)
+
+def pageRFC(rfcnum):
+    rfcnum = (str(rfcnum)).lower()  # In case argparse interprets it as an int or it's entered in uppercase
+    with urlopen('https://tools.ietf.org/rfc/rfc{0}.txt'.format(rfcnum)) as rfc:
+        pydoc.pager(rfc.read().decode('utf-8'))
+
+def parseArgs():
+    args = argparse.ArgumentParser(description = 'RFC Downloader/Viewer',
+                                    epilog = 'TIP: this program has context-specific help. e.g. try "%(prog)s d -h"\nhttps://square-r00t.net/')
+    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?
+    downloadargs.add_argument('-d',
+                        '--destination',
+                        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.')
+    return(args)
+
+def main():
+    argsin = parseArgs()
+    args = argsin.parse_args()
+    if args.operation == 'd':
+        downloadRFC(args.destdir, args.rfcnum)
+    elif args.operation == 'p':
+        pageRFC(args.rfcnum)
+    else:
+        argsin.print_help()   
+
+if __name__ == '__main__':
+    main()