Features
- Multithreaded indexing and searching
- Multiline fuzzy search of multiple files or a single file
- Swap between multi-file view and single file view on the fly
- Content view pane that shows the snippet surrounding the search result selected
- Text editor and PDF viewer integration
Text editor integration
Docfd uses the text editor specified by $VISUAL (this is checked first) or $EDITOR.
Docfd opens the file at first line of search result for the following editors:
nanonvim/vim/vikakhxemacsmicrojed/xjed
PDF viewer integration
Docfd guesses the default PDF viewer based on the output of xdg-mime query default application/pdf, and invokes the viewer either directly or via flatpak depending on where the desktop file can be first found in the list of directories specified by $XDG_DATA_DIRS.
Docfd opens the file at first page of the search result and starts a text search of the most unique word of the matched phrase within the same page for the following viewers:
Docfd opens the file at first page of the search result for the following viewers:
Installation
Statically linked binaries are available via GitHub releases.
Docfd is also packaged on:
Notes for packagers: Outside of the OCaml toolchain for building (if you are packaging from source), Docfd also requires the following external tools at run time for full functionality:
pdftotext from poppler-utils for PDF supportpandoc for support of .epub, .odt, .docx, .fb2, .ipynb, .html, and .htm filesfzf for file selection menu
Launching
Read from piped stdin
command | docfd
Docfd uses single file view when source of document is piped stdin.
No paths should be supplied as arguments in this case. If any paths are specified, then stdin is ignored.
Scan for files
docfd [PATH]...
The list of paths can contain directories. Each directory in the list is scanned recursively for files with one of the following extensions by default:
You can change the file extensions to use via --exts, or add onto the list of extensions via --add-exts.
If the list PATHs is empty, then Docfd defaults to scanning the current directory ..
If any of the file ends with .pdf, then pdftotext is required to continue.
If exactly one file is specified in the list of paths, then Docfd uses single file view. Otherwise, Docfd uses multi-file view.
Scan for files then select with fzf
docfd [PATH]... ?
The ? can be in any position in the path list. If any of the path is ?, then file selection of the discovered files via fzf is invoked.
Use list of paths from file
docfd [PATH]... --paths-from paths.txt
The final list of paths used is then the concatenation of PATHs and paths listed in paths.txt, which has one path per line.
The list PATHs does not default to . when --paths-from is used.
Searching
The search field takes a search expression as input. A search expression is one of:
- Search phrase, e.g.
fuzzy search ?expression (optional)(expression)expression | expression (or), e.g. go ( left | right )
To use literal ?, (, ) or |, a backslash (\) needs to be placed in front of the character.
Optional operator handling specifics
For a phrase with optional operator, such as ?word0 word1 ..., the first word is grouped implicitly, i.e. it is treated as ?(word0) word1 ....
Search phrase and search procedure
Document content and user input in the search field are tokenized/segmented in the same way, based on:
- Contiguous alphanumeric characters
- Individual symbols
- Individual UTF-8 characters
- Spaces
A search phrase is a list of said tokens.
Search procedure is a DFS through the document index, where the search range for a word is fixed to a configured range surrounding the previous word (when applicable).
A token in the index matches a token in the search phrase if they fall into one of the following cases:
- They are a case-insensitive exact match
- They are a case-insensitive substring match (token in search phrase being the substring)
- They are within the configured case-insensitive edit distance threshold
Search results are then ranked using heuristics.
Common controls between multi-file view and single file view
Navigation mode
Search mode
- Search field is active in this mode
Enter to confirm search phrase and exit search mode
Multi-file view
The default TUI is divided into four sections:
- Left is the list of documents which satisfy the search phrase
- Top right is the content view of the document which tracks the search result selected
- Bottom right is the ranked search result list
Bottom pane consists of:
- Status bar
- Key binding info
- File content requirement field
- Search field
Controls
Docfd operates in modes, the initial mode is navigation mode.
Navigation mode
Scroll down the document list
j- Down arrow
- Page down
- Scroll down with mouse wheel when hovering above the area
Scroll up the document list
k- Up arrow
- Page up
- Scroll up with mouse wheel when hovering above the area
Scroll down the search result list
Shift+JShift+Down arrowShift+Page down- Scroll down with mouse wheel when hovering above the area
Scroll up the document list
Shift+KShift+Up arrowShift+Page up- Scroll up with mouse wheel when hovering above the area
Open document
Enter
- Docfd tries to use
$VISUAL first, if that fails then Docfd tries $EDITOR
Switch to single file view
Single file view
If the specified path to Docfd is not a directory, then single file view is used.
In this view, the TUI is divided into only two sections:
- Top is ranked search result list
- Bottom is the search interface
Controls
The controls are simplified in single file view, namely Shift is optional for scrolling through search result list.
Navigation mode
Scroll down the search result list
j- Down arrow
- Page down
Shift+JShift+Down arrowShift+Page down- Scroll down with mouse wheel when hovering above the area
Scroll up the document list
k- Up arrow
- Page up
Shift+KShift+Up arrowShift+Page up- Scroll up with mouse wheel when hovering above the area
Open document
Enter
- Docfd tries to use
$VISUAL first, if that fails then Docfd tries $EDITOR
Switch to multi-file view
Limitations
File auto-reloading is not supported for PDF files, as PDF viewers are invoked in the background via shell. It is possible to support this properly in the ways listed below, but requires a lot of engineering for potentially very little gain:
- Docfd waits for PDF viewer to terminate fully before resuming, but this prohibits viewing multiple search results simultaneously in different PDF viewer instances.
- Docfd manages the launched PDF viewers completely, but these viewers are closed when Docfd terminates.
- Docfd invokes the PDF viewers via shell so they stay open when Docfd terminates. Docfd instead periodically checks if they are still running via the PDF viewers' process IDs, but this requires handling forks.
- Outside of tracking whether the PDF viewer instances interacting with the files are still running, Docfd also needs to set up file update handling either via
inotify or via checking file modification times periodically.
Acknowledgement
- Demo gifs are made using vhs.
- ripgrep-all for text extraction software choices
