Add: Merge command to merge multiples file

README.md

@@ -36,12 +36,12 @@
 - **PDF** → Images (JPG)
 - **PDF** → Text (TXT) - Extract text content from PDF files
 - **PDF Info** → Display metadata (title, creator, page count, file size)
+- Merge multiple PDFs
 
 #### Coming Soon
 - PowerPoint → PDF
 - Excel → PDF
 - HTML → PDF
-- Merge multiple PDFs
 - PDF compression
 - PDF text extraction
 
@@ -158,6 +158,22 @@ filto extract input.pdf -o extracted.txt
 ```
 filto extract input.pdf --page 1 --output page1.txt
 ```
+---
+### 5. Merge PDF Files
+Merge multiple PDF files into a single PDF
+
+**Basic usage:**
+```
+filto merge file1.pdf file2.pdf output.pdf
+```
+
+**Example with multiple files:**
+```
+filto merge doc1.pdf doc2.pdf doc3.pdf merged_output.pdf
+```
+
+> **Note:** You need to provide at least two PDF files to merge. The last argument will be used as the output file.
+
 ---
 ## Contributing
 

package.json

@@ -17,6 +17,7 @@
     "@oclif/plugin-plugins": "^5",
     "asposepdfnodejs": "^25.10.0",
     "image-to-pdf": "^3.0.2",
+    "pdf-lib": "^1.17.1",
     "pdf-parse": "^2.4.5",
     "rewiremock": "^3.14.6"
   },

src/commands/merge/index.ts

@@ -0,0 +1,35 @@
+import { Args, Command, Flags } from '@oclif/core'
+import { MergePdfs } from '../../merge/index.js';
+export default class Merge extends Command {
+  static override description = ' Merge multiple PDFs'
+
+  static override args = {
+    inputs: Args.string({ description: 'Input PDF files to merge', required: true, multiple: true }),
+    output: Args.string({ description: 'Output merged PDF file', required: true }),
+  }
+  static override strict = false;
+
+  public async run(): Promise<void> {
+    const { args } = await this.parse(Merge)
+    const { inputs } = args;
+
+    if (inputs.length < 2) {
+      this.error('Please provide at least two PDF files to merge.');
+    }
+
+    try {
+      const argv = process.argv;
+      const inputsArr = argv.slice(3, argv.length - 1);
+      const result = await MergePdfs(inputsArr, argv[argv.length - 1]);
+
+      if (result.success) {
+        this.log(result.message);
+      } else {
+        this.error(result.message);
+      }
+    } catch (error: any) {
+      this.error(`Unexpected error during merge: ${error.message}`);
+    }
+
+  }
+}

src/merge/index.ts

@@ -0,0 +1,42 @@
+
+import { PDFDocument } from 'pdf-lib';
+import fs from 'fs';
+import ConversionResult from '../types/converstionResult.js';
+
+export async function MergePdfs(inputPdf: string[], output: string = "merged.pdf"): Promise<ConversionResult> {
+    if (!fs.existsSync(inputPdf[0])) {
+        return {
+            success: false,
+            message: `Input file not found: ${inputPdf}`
+        };
+    }
+
+    try {
+        const pdfToMerge = inputPdf.map(filePath => fs.readFileSync(filePath));
+
+        const mergedPdf = await PDFDocument.create();
+        for (const pdfBytes of pdfToMerge) {
+            const pdf = await PDFDocument.load(pdfBytes);
+            const copiedPages = await mergedPdf.copyPages(pdf, pdf.getPageIndices());
+            copiedPages.forEach((page) => {
+                mergedPdf.addPage(page);
+            });
+        }
+
+        const buf = await mergedPdf.save();
+        fs.writeFileSync(output, buf);
+
+        return {
+            success: true,
+            message: `Successfully Merged PDFs: ${inputPdf.map(pdf => {
+                return pdf
+            })} into -> ${output}`
+        };
+    } catch (error: any) {
+        return {
+            success: false,
+            message: `Error during Merge: ${error.message}`,
+            error
+        };
+    }
+}