Searching

There are four kinds of search, from the narrowest to the widest.

And there is one comparison, :diff, which shows what changed between two versions of a paper.

In this PDF, with /#

Type / and a word. The search is incremental, so while you type, the view goes to the first match after where you were.

Every match on screen is highlighted, and the message says which one you are at ("match 3 of 17", for documents up to 150 pages). The search is smart case, so a query with a capital letter matches case exactly, and otherwise it does not.

Recent files, with \o#

\o (or :recent) lists the files you opened, most recent first. Type parts of the name to filter.

Every PDF on your computer, with \f#

\f (or :find) lists every PDF in the folders of pdf_dirs (your home folder by default), newest first, and filters them as you type. Hidden folders (.cache, .local, …), folders of programs (node_modules, site-packages, build, …) and network or cloud mounts are skipped. The whole home folder is scanned in about a second, in the background; the list of the previous scan shows at once.

Typing in both lists is fuzzy, so the letters of a word must appear in order, not necessarily together (bstshl finds bistable-shells.pdf). Several words separated by spaces may be in any order and may match the folders too (2024 shells); a word found in the file name counts more than one found only in a folder name.

Inside every PDF, with \/ and \n#

\/ (or :library words) searches the text of every PDF in pdf_dirs. \n (or :comments words) searches every comment and highlighted text in them. Tab switches between the two.

• The words may be in any order but must all be on the same page; pages where they appear together as you typed them come first, then the newest files.
• Upper and lower case do not matter (for letters without accents; é must be typed as é).
• Each result shows the file, the page and the passage, with the words coloured. In \n it also shows the highlight's colour, the comment and the highlighted text.
• With nothing typed, \n lists every comment you ever wrote, newest files first.
• Ctrl-t (or :tasks) keeps only the tasks still to do, from every PDF, which is your to-do list across all your papers (see Highlights and comments).
• Enter opens the PDF at that page with the words highlighted; n and N go on to the next matches in that PDF.

The index#

To make this fast, the text of your PDFs is kept in an index. It is made the first time you press \/ or \n, by three background processes at low priority, so you can keep reading (and searching what is already indexed) meanwhile; the top right corner shows the progress ("indexing 1234 / 14195").

• The first time takes about 16 ms per PDF (about 4 minutes for 14 000 PDFs). Afterwards only new or changed files are read again, which takes a fraction of a second.
• It lives in ~/.cache/nomadys-pdf/index2, about 9 KB per PDF (compressed). Deleting that folder is safe, because it is made again. (The index of versions before tasks, index, is removed and made again once.)
• A broken PDF cannot crash the reader, because the index is made by separate processes, and a PDF that crashes one is skipped until it changes.
• PDFs with a password and scanned PDFs without a text layer have no text to index.
• Folders on network drives or cloud mounts (FUSE, NFS, SMB) are skipped, since reading them could download every file.

A search over 2 700 PDFs answers in under 0.2 s.

Comparing two versions with :diff#

:diff old-version.pdf compares the PDF on screen with an older version, word by word.

• new text is shaded green
• changed text is shaded amber
• a red mark shows where text was deleted

]c / [c go to the next / previous change, and the message says what the old text was, such as "change 3 of 9: changed, was “0.47”". :nodiff hides it. Nothing is written into the PDF.

The notes are compared too, including highlights, comments (and their replies), text boxes, pictures and drawings. A frame is drawn round each one that is new (green), changed (amber, because its comment or text is different) or removed (red, where it was), and ]c takes you through them together with the changes in the text, with messages such as "new highlight “check this value”" and "text box changed, was “Hello”, now “Hello world”". A note is the same one in both versions when it has the same name inside the PDF or, without one, the same kind in the same place. If nothing differs the message says "no change in the text or the notes".

Figures and anything that is not text or a note are not compared.

The comparison ignores what is not a real change, such as words hyphenated at the end of a line, ligatures (fi, fl) and page numbers, so text that only moved to another page does not show up. When LaTeX recompiles the PDF, the comparison is made again automatically, which is handy when answering reviewers.