pdfium-auto

Auto-download and cache PDFium binaries at runtime — zero-friction setup for pdfium-render.

Problem

pdfium-render is excellent, but requires users to manually:

Run a setup script to download 30 MB of platform-specific binaries
Export DYLD_LIBRARY_PATH / LD_LIBRARY_PATH before running

This blocks cargo install workflows: users cannot simply cargo install edgequake-pdf2md && pdf2md document.pdf.

Solution

pdfium-auto wraps pdfium-render with automatic library management:

Step	Before	After
Install	`cargo install && ./scripts/setup-pdfium.sh`	`cargo install`
Setup	`export DYLD_LIBRARY_PATH=$(pwd)`	(nothing)
First run	Error: cannot find `libpdfium.dylib`	Download → cache → run
Subsequent runs	Needs env var	Instant start from cache

Usage

use pdfium_auto::{bind_pdfium_silent, ensure_pdfium_library};

// One-shot: download if needed, then bind
let pdfium = bind_pdfium_silent().expect("PDFium unavailable");

// Download with progress callback
let path = ensure_pdfium_library(Some(&|downloaded, total| {
    match total {
        Some(t) => eprint!("\rDownloading PDFium: {}%", downloaded * 100 / t),
        None    => eprint!("\rDownloading PDFium: {} bytes", downloaded),
    }
})).expect("download failed");

Cache Locations

Platform	Default cache path
macOS	`~/Library/Caches/pdf2md/pdfium-{VERSION}/`
Linux	`~/.cache/pdf2md/pdfium-{VERSION}/`
Windows	`%LOCALAPPDATA%\pdf2md\pdfium-{VERSION}\`

Environment Variables

Variable	Purpose
`PDFIUM_LIB_PATH`	Full path to existing pdfium library; skips download
`PDFIUM_AUTO_CACHE_DIR`	Override the base cache directory

Platform Support

OS	Arch	Library
macOS	arm64 (Apple Silicon)	`libpdfium.dylib`
macOS	x86_64 (Intel)	`libpdfium.dylib`
Linux	x86_64	`libpdfium.so`
Linux	aarch64	`libpdfium.so`
Windows	x86_64	`pdfium.dll`
Windows	aarch64	`pdfium.dll`

License

MIT OR Apache-2.0

pdfium-auto 0.1.0