NWA-PCUG Newsletter Article
Rabbit in a MIME Field
Ed Maxey, June 99
firstname.lastname@example.org (click to email author)
John Clark, our NWAPCUG Software librarian, fancies all sorts of electronic gadgets. He recently acquired a digital camera, snapped an image of a back yard rodent and emailed it to me. A dentist brother would like to get the picture but his AOL did not seem to receive the image when John's email was forwarded.
John's email to the POL (Physicians' Online) address was then forwarded by me to me on the AOL address. The picture was apparently not received by AOL here either. A search of the computer revealed that rabbit.jpg was not even on the hard drive. Yet, the rabbit was clearly seen on POL. Is this not a mystery?
A telephone call to AOL's technical staff revealed that AOL does not re- convert, from MIME back to binary, any attachments beyond certain sizes. The technician did not know what the determining size factor was. He did indicate that MIME was readily decoded by WINZIP which could be downloaded from www.winzip.com.
What is MIME? The dictionary says it is "to mimic; ape." Is it not rather difficult to see how pages of garbage, by any stretch of the imagination, can mimic a cotton tail? Anyway, this seeming chaos uses printable ACII characters to transmit binary code on the Internet. MIME is but one of several encoding techniques used. MIME is a computer acronym for Multipurpose Internet Mail Extension.
WINZIP70.EXE was downloaded (Note: version 7.0 is also available on the NWA-PCUG BBS) and installed without difficulty. WINZIP's Online Manual is quite helpful. Here's some of what it says;
- "You do not need to worry if the file being received is UUencoded,
- XXencoded, BinHex, or a MIME file (base64, plain/text, and
- quoted-printable). WinZip will detect the method being used and
- automatically decode it....
- "You can also open a file using WinZip's Open toolbar button, or drag
- and drop a file into WinZip, regardless of the file's extension."
Very interesting. One only needs to get the encoded file containing the bunny's picture. Simple enough you say. Maybe.
The email from John was originally received through POL (Physicians' Online). POL uses NETSCAPE as its browser. Prior explorations had revealed that all the stored email was in a single file named INBOX. If INBOX could be loaded into an editor one might cut and paste a MIME segment into a separate file for decoding by WINZIP. Well, INBOX was a large file, something over 10 megabytes. The Windows98 Notebook would not load it. Windows98's WordPad tried to load the file and crashed; no keyboard, no mouse, no nothing. The only option was to reboot.
DOS programs do still run in 1999. One such is Vernon Buerg's LIST.COM (list91m.zip is available on the BBS). LIST wasn't intimidated by the 10 megabyte INBOX file. John Clark had used the word "critter" in his emailing so LIST was instructed to search INBOX for this term. The second incidence of "critter" was followed by the rabbit.jpg file in MIME format. It was preceded with a numbered marker and followed by pages of chaotic characters. Here's a portion:
Now LIST really showed its stuff. A second search, this time for "44BA2," brought up the beginning of the MIME segment. Alt-M was entered to mark the top line. F3 brought up the next occurrence of "44BA22" and Alt-B was used to mark the bottom line. Alt-D brought up the Copy To File function and the MIME section was copied to D:\PETER.TXT. How about that? LIST not only thrives on files so big they bombed Windows98, it will also copy a specific section of a large file to a much smaller text file in another location. Kudos to Vernon Buerg's LIST.
EXIT took me back to Windows where a double click on My Computer and a second double click on the D:drive icon showed that PETER.TXT was indeed there. Thank you Mr.Buerg. So far so good.
WINZIP70 was run and presented several options. A click on Open brought up a second window which allows one to select the drive, folder and file to be processed. D:\PETER was selected and a second Open option clicked. The next screen showed two files, 0001.txt and rabbit.jpg. It was this latter file which required reconstruction if the digital image was to be seen.
A click on rabbit.jpg highlighted this option and a click on Extract brought up another window with options for locating the reconstructed jpg file. D:\ was selected and followed by clicking on Extract.
At this point double clicks on My Computer, on the D: drive icon and on the rabbit.jpg icon produced an intriguing color photo image of a rabbit peacefully nibbling grass in John Clark's back yard.
Summary 1. John Clark emailed rabbit.jpg as an attached jpg file, 2. Netscape embedded the file in MIME format inside its INBOX file, 3. LIST copied the embedded portion to PETER.TXT, 4. WINZIP70 reconstructed the file to its image/jpeg format and 5. Windows Internet Explorer then showed the picture.
At this juncture we still have not solved our mystery. What happened to the rabbit.jpg file when it was forwarded from POL to AOL? You, like the AOL tech staff, will never never never guess.
John's email contained "got a new critter in my back yard..." as its subject item. When receiving the forwarded email AOL did not display the image. Rather it created a file, GOTANEWC.TXT, in the AOL32BIT/DOWNLOAD folder. WINIP70 recovered rabbit.jpg from GOTANEWC.TXT just as it had previously recovered it from PETER.TXT.
You folks who get family photos through AOL easily scroll them onscreen most of the time. Occasionally you'll encounter a MIME file. It can be viewed with a modicum of effort. You'll likely need to find a recent TXT file of strange name in your AOL/DOWNLOAD folder and decode it. If you have not already done so, these tasks may appear difficult or even too intimidating to be worth the effort. Looking back, after rescuing a rabbit from a MIME field, the reward is more than worth the effort.
Happy MIME image viewing to all.
ADDENDUM: For MIME details see "Bits, Bytes, OR Why Do We Get E-mail We Can't Read?", by John Clark, NWA-PCUG Newsletter, MAR '97, p 11. The article may also be found on our web page at www.pcgroup.nwark.com.Click here to return to top