pdf

PDF Processing Library

A cross-platform Go library for PDF processing operations: info extraction, splitting, and conversion to images.

Installation

go get github.com/yaoapp/gou/pdf

System Dependencies

macOS

# Install via Homebrew
brew install poppler      # for pdftoppm
brew install mupdf-tools   # for mutool
brew install imagemagick   # for convert

Linux (Ubuntu/Debian)

# Install via apt
sudo apt install poppler-utils  # for pdftoppm
sudo apt install mupdf-tools    # for mutool
sudo apt install imagemagick    # for convert

Linux (CentOS/RHEL)

# Install via yum/dnf
sudo yum install poppler-utils   # for pdftoppm
sudo yum install mupdf           # for mutool
sudo yum install ImageMagick     # for convert

Windows

Windows support is not yet implemented. Contributions welcome.

Usage

Basic Usage

package main

import (
    "context"
    "fmt"
    "github.com/yaoapp/gou/pdf"
)

func main() {
    // Create PDF processor
    p := pdf.New(pdf.Options{
        ConvertTool: pdf.ToolMutool,
        ToolPath:    "/usr/local/bin/mutool", // optional custom path
    })

    ctx := context.Background()

    // Get PDF info
    info, err := p.GetInfo(ctx, "document.pdf")
    if err != nil {
        panic(err)
    }
    fmt.Printf("Pages: %d\n", info.PageCount)

    // Split PDF
    files, err := p.Split(ctx, "document.pdf", pdf.SplitConfig{
        OutputDir:    "./output",
        OutputPrefix: "page",
        PageRanges:   []string{"1-5", "6-10"}, // or use PagesPerFile: 5
    })
    if err != nil {
        panic(err)
    }

    // Convert to images
    images, err := p.Convert(ctx, "document.pdf", pdf.ConvertConfig{
        OutputDir:    "./images",
        OutputPrefix: "page",
        Format:       "png",
        DPI:          150,
        PageRange:    "1-10",
    })
    if err != nil {
        panic(err)
    }

    fmt.Printf("Generated %d images\n", len(images))
}

Available Tools

• pdf.ToolPdftoppm - Uses poppler-utils (recommended for Linux)
• pdf.ToolMutool - Uses MuPDF tools (recommended for macOS)
• pdf.ToolImageMagick - Uses ImageMagick convert

Configuration Options

// Create with custom tool and path
p := pdf.New(pdf.Options{
    ConvertTool: pdf.ToolPdftoppm,
    ToolPath:    "/custom/path/to/pdftoppm",
})

// Split configuration
splitConfig := pdf.SplitConfig{
    OutputDir:    "./output",
    OutputPrefix: "chapter",
    PageRanges:   []string{"1-10", "11-20"},  // specific ranges
    // OR
    PagesPerFile: 5,                          // pages per file
}

// Convert configuration
convertConfig := pdf.ConvertConfig{
    OutputDir:    "./images",
    OutputPrefix: "slide",
    Format:       "jpg",        // png, jpg, jpeg
    DPI:          300,          // resolution
    Quality:      95,           // JPEG quality (1-100)
    PageRange:    "all",        // "all", "1-5", "3"
}

API Reference

New(opts Options) *PDF

Creates a new PDF processor with specified options.

GetInfo(ctx context.Context, filePath string) (*Info, error)

Extracts PDF metadata and page count.

Split(ctx context.Context, filePath string, config SplitConfig) ([]string, error)

Splits PDF into multiple files based on page ranges.

Convert(ctx context.Context, filePath string, config ConvertConfig) ([]string, error)

Converts PDF pages to images.

Error Handling

The library returns descriptive errors for common issues:

• Tool not found or not available
• Invalid configuration
• File access problems
• Conversion failures

Handle tool availability errors:

import "strings"

// Handle tool availability errors
images, err := p.Convert(ctx, "document.pdf", convertConfig)
if err != nil {
    if strings.Contains(err.Error(), "not available") {
        fmt.Println("Required conversion tool not available")
    }
    return err
}