gpdf

README

gPDF

A library for reading, searching, and modifying PDF documents.

Features

• Read Content: Extract text, images, and layout information from PDF files.
• Search: Find keywords across pages.
• Modify: Replace text content and save back to PDF.
• Table Detection: Identify table-like structures in PDF layouts.
• Image Extraction: Extract images from PDF pages with color space conversion support.

Usage

Reading a PDF

pdf, err := doc.Open("example.pdf")
if err != nil {
    log.Fatal(err)
}
defer pdf.Close()

text, err := pdf.ReadContent()
if err == nil {
    fmt.Println(text)
}

Searching and Replacing

err := pdf.Replace("Old Text", "New Text")
if err != nil {
    log.Fatal(err)
}

f, _ := os.Create("modified.pdf")
err = pdf.Save(f)
f.Close()

Table Detection

tables, err := pdf.ReadTables()
if err != nil {
    log.Fatal(err)
}

for _, pageTables := range tables {
    for _, table := range pageTables {
        fmt.Printf("Table at (%f, %f)\n", table.X, table.Y)
    }
}

Merging PDFs

doc1, _ := doc.Open("file1.pdf")
doc2, _ := doc.Open("file2.pdf")
defer doc1.Close()
defer doc2.Close()

merged, err := doc.Merge(doc1, doc2)
if err != nil {
    log.Fatal(err)
}
defer merged.Close()

f, _ := os.Create("merged.pdf")
merged.Save(f)
f.Close()

Merging from Remote Sources (URL/S3)

You can open PDFs from any io.ReaderAt (like a memory buffer, URL, or S3 object):

resp, _ := http.Get("https://example.com/file.pdf")
data, _ := io.ReadAll(resp.Body)
resp.Body.Close()

// Open from memory
reader := bytes.NewReader(data)
pdf, _ := doc.OpenReader(reader, int64(len(data)))
defer pdf.Close()

// Merge with other documents
merged, _ := doc.Merge(doc1, doc2, pdf)