Making a PDF that's larger than Germany • Hacker News Board

Re: Making a PDF that's larger than Germany

#41

Post by worewood » Thu, Feb 01, 2024, 3:41 AM UTC

chaxor wrote: post #35

anotheraccount9 wrote: post #14

For a moment I wasn't sure if I wanted to click on the link.

On an only slightly related note: is there any good way to check PDFs for malware/executables? If I'm stuck with an attempt at it, the best I can think of is opening in a new QEMU or docker with no Internet access, but that's 1) a fair but of work to check something, and 2) probably not even that secure. Using some cli tool, like xxx, bat, or ranger, that does some processing to extract the text and looking at just t…

What you mean with "PDFs with malware/executables"?

If you're talking about embedded active content within them, then a reader application can just ignore/not run it.

If you're talking about a crafted PDF that exploits, let's say, font rendering bugs inside the reader than it's near impossible. Keep your applications updated.

Re: Making a PDF that's larger than Germany

#42

Post by yannis » Thu, Feb 01, 2024, 3:51 AM UTC

And of course you can try and produce this pdf using TeX. In this post https://tex.stackexchange.com/a/27482/963 I created a pdf of 15283 pages (lettersize) filled with lorem ipsum text and without the program running out of memory.

Re: Making a PDF that's larger than Germany

#43

Post by wiradikusuma » Thu, Feb 01, 2024, 4:01 AM UTC

I open the PDF in Google Chrome on a Mac. When I Ctrl+P, the dialog says it's 1 Page. I don't try to print it, but I think it will not consume more than 1 page?

Also, PDF preview in Chrome simply showing it like a normal PDF, but Preview seems confused (gray background instead of white)?

Re: Making a PDF that's larger than Germany

#44

Post by matheusmoreira » Thu, Feb 01, 2024, 4:33 AM UTC

0134340 wrote: post #29

>Please don’t try to print it. Sounds like a print bomb waiting to happen. Last time I had a printer it was next to impossible to cancel a print job on Windows. Back when people had wifi printers that were open or ill-secured, those were fun times.

> it was next to impossible to cancel a print job on Windows

It's still impossible. The only reliable method I've found consists of turning the printer off and then deleting the print job in the queue. Only way to get Windows to actually delete it. Doesn't work unless the printer is sitting right next to me, of course. I have no idea why this is so hard.

Re: Making a PDF that's larger than Germany

#45

Post by nayuki » Thu, Feb 01, 2024, 4:35 AM UTC

I'll analyze PNG for comparison. The largest width and height is 2147483647 (2^31 - 1). Using the pHYs chunk (physical pixel dimensions), the lowest density we can specify is 1 pixel per metre. So, 2 billion metres (2 gigametres) is somewhat bigger than the diameter of the sun at 1.39 Gm. https://en.wikipedia.org/wiki/Orders_of_magnitude_(length)#g...

Using the sCAL chunk (physical scale) would allow extremely large dimensions because it uses ASCII floating-point.

Re: Making a PDF that's larger than Germany

#46

Post by jancsika » Thu, Feb 01, 2024, 4:53 AM UTC

kepano wrote: post #4

I cannot let this opportunity go by without quoting On Exactitude in Science by Borges in its entirety ". . . In that Empire, the Art of Cartography attained such Perfection that the map of a single Province occupied the entirety of a City, and the map of the Empire, the entirety of a Province. In time, those Unconscionable Maps no longer satisfied, and the Cartographers Guilds struck a Map of the Empire whose size w…

There are some funny lines from They Might Be Giants' "Women and Men" that run along the same lines:

Women and men have crossed the ocean,

They now begin to pour

Out from the boat and up the shore.

Two by two they enter the jungle,

And soon they number more,

Three by three as well as four by four.

Soon the stream of people gets wider,

Then it becomes a river,

River becomes an ocean,

Carrying ships that bear

Women and men.

**

Borges: map of an area gets so detailed it becomes the same size as the area.

TMBG: creatures multiply and ultimately overrun an area so fully that their group behavior recreates the ecology of the area they took over

Re: Making a PDF that's larger than Germany

#47

Post by wodenokoto » Thu, Feb 01, 2024, 4:55 AM UTC

mrb wrote: post #11

Fun experiment alexwlchan! Two small mistakes in your post: you write "15,000,000,000.00 in" and "that the size of a page is 15 billion inches", but it should be 15 million. You said you had difficulty formatting text. Here is a "hello world" pdf that just has these two words on a page: copy and paste this text (stripping leading spaces on each line) and save it in a .pdf file. Basically in order to write text you ha…

> "15,000,000,000.00 in" and "that the size of a page is 15 billion inches", but it should be 15 million.

Can you help me count zeroes? Why is it million and not billion?

Re: Making a PDF that's larger than Germany

#48

Post by peddling-brink » Thu, Feb 01, 2024, 5:06 AM UTC

chaxor wrote: post #35

anotheraccount9 wrote: post #14

For a moment I wasn't sure if I wanted to click on the link.

On an only slightly related note: is there any good way to check PDFs for malware/executables? If I'm stuck with an attempt at it, the best I can think of is opening in a new QEMU or docker with no Internet access, but that's 1) a fair but of work to check something, and 2) probably not even that secure. Using some cli tool, like xxx, bat, or ranger, that does some processing to extract the text and looking at just t…

For analysis, I’ve used Didier’s tools. If you just want a safe way to open it, upload it to a cloud storage provider which destructively renders the pdf. Box or Google drive should work.

https://blog.didierstevens.com/programs/pdf-tools/

Re: Making a PDF that's larger than Germany

#49

Post by jetrink » Thu, Feb 01, 2024, 5:20 AM UTC

wodenokoto wrote: post #47

mrb wrote: post #11

Fun experiment alexwlchan! Two small mistakes in your post: you write "15,000,000,000.00 in" and "that the size of a page is 15 billion inches", but it should be 15 million. You said you had difficulty formatting text. Here is a "hello world" pdf that just has these two words on a page: copy and paste this text (stripping leading spaces on each line) and save it in a .pdf file. Basically in order to write text you ha…

> "15,000,000,000.00 in" and "that the size of a page is 15 billion inches", but it should be 15 million. Can you help me count zeroes? Why is it million and not billion?

The numerical and word versions are equal, but they're both wrong. 15 billion inches is to the distance from the Earth to the Moon.

Re: Making a PDF that's larger than Germany

#50

Post by croes » Thu, Feb 01, 2024, 5:22 AM UTC

wodenokoto wrote: post #47

mrb wrote: post #11

Fun experiment alexwlchan! Two small mistakes in your post: you write "15,000,000,000.00 in" and "that the size of a page is 15 billion inches", but it should be 15 million. You said you had difficulty formatting text. Here is a "hello world" pdf that just has these two words on a page: copy and paste this text (stripping leading spaces on each line) and save it in a .pdf file. Basically in order to write text you ha…

> "15,000,000,000.00 in" and "that the size of a page is 15 billion inches", but it should be 15 million. Can you help me count zeroes? Why is it million and not billion?

>If we crank it all the way up to the maximum of UserUnit 75000, Acrobat now reports the size of our page as 15,000,000,000.00 x 15,000,000,000.00 in – 381 km along both sides, matching the original claim. If you’re curious, you can download the PDF.

15 billion inches are 381,000km. The original claim is the limit is 15 million inches.