Step-by-step instructions for creating PDFs from any file type, including methods for merging, compressing and password-protecting PDF documents securely.

All products featured here are independently selected by our editors and writers. If you buy something through links on our site, Mashable may earn an affiliate commission. Kindles used to only ...

You use the chmod command to set each of these permissions. To see what permissions have been set on a file or directory, we ...