We go today down through the catacombs into the cave of wonders. Most are afraid to go down there but if you remember to only touch the lamp, you'll be OK. I'll explain it in a different format so that you'll get it. Carpenters all over the world know you measure twice and cut once. So you read the formula, type the recipe, check that it is correct, then hit the return buttom. Simple.
We are talking about the terminal window or command line in Linux. It's sort of like the similar terminal window on the Microsoft OS but in a different neighborhood. OK, we all know you have been to trained to push the icon on your smart phone, tablet and PC, get over it. I will drag you through the process of this discovery. Cave of wonders, remember.
First I wanted to take a book that was a folder of scanned pages (JPG files) and turn them into a PDF document so that it was easier to handle and read. I tried a number of applications thinking it would be easy. No one application could do what I wanted to do. I was looking at converting and compiling and editing.
Second, when in jeapordy put your answer in the form of a question and Google it or Yahoo it or..... My question, (how to) "turn multiple jpg pages into pdf document in Ubuntu." Scanning down the results and bypassing all the add this application and that (you have to learn how to use each application!) there was the convert command. The person described what it was and how to use it. I took the folder with the files in it and copied it on my desktop, then opened the terminal, typed in his formula using my folder names instead of his:
cd Desktop -- change to desktop
cd tim -- change to "tim" folder on desktop
convert *.jpg timbuktu.pdf -- convert all the "tim" folders ,jpg files to a single pdf file named "timbuktu.pdf. Use a carriage return or enter key after each line. Remember the carpenter rule, the first time I did it, it did not work. Then I put a space between convert and *, it work more than fine and fast. When I opened the "timbuktu.pdf file there, low-n-behold, was my book in PDF format, no extra work on my part.
Linux has a lot of commands in it's cave of wonders, but we like GUIs and Icon. I problem is that the pretty covers are usually ganged functions for ease of use. The command line is often more articulate and precise. Either obtain a book on the subject or Google like I did. The convert command is built into Linux, we never knew it was there, now we do. Come on now, I saved you from installing and learning 3 different applications and don't trip over the flying carpet.