#1 Allowing to specify the pdftk executable.

Author: kevbite

src/Kevsoft.PDFtk/PDFtk.cs

@@ -16,9 +16,16 @@ public sealed class PDFtk : IPDFtk
         /// Initializes a new instance of the PDFtk class.
         /// </summary>
         public PDFtk()
+            : this(PDFtkOptions.Default())
+        {
+        }
+        
+        /// <inheritdoc cref="PDFtk()"/>
+        /// <param name="options">The options to use.</param>
+        public PDFtk(PDFtkOptions options)
         {
             _xfdfGenerator = new XfdfGenerator();
-            _pdftkProcess = new PDFtkProcess();
+            _pdftkProcess = new PDFtkProcess(options);
         }
 
         /// <inheritdoc/>
@@ -61,16 +68,16 @@ public PDFtk()
         public async Task<IPDFtkResult<byte[]>> GetPagesAsync(byte[] pdfFile, params int[] pages)
         {
             using var inputFile = await TempPDFtkFile.FromAsync(pdfFile);
-            
+
             return await GetPagesAsync(inputFile.TempFileName, pages);
         }
-        
-        
+
+
         /// <inheritdoc/>
         public async Task<IPDFtkResult<byte[]>> GetPagesAsync(Stream pdfFile, params int[] pages)
         {
             using var inputFile = await TempPDFtkFile.FromAsync(pdfFile);
-            
+
             return await GetPagesAsync(inputFile.TempFileName, pages);
         }
 
@@ -127,7 +134,7 @@ public async Task<IPDFtkResult<IDataField[]>> GetDataFieldsAsync(byte[] pdfFile)
 
             return await GetDataFieldsAsync(inputFile.TempFileName);
         }
-        
+
         /// <inheritdoc/>
         public async Task<IPDFtkResult<IDataField[]>> GetDataFieldsAsync(Stream pdfFile)
         {
@@ -160,7 +167,7 @@ public async Task<IPDFtkResult<byte[]>> ConcatAsync(IEnumerable<byte[]> pdfFiles
             var inputFiles = await Task.WhenAll(
                 pdfFiles.Select(async file => await TempPDFtkFile.FromAsync(file))
                     .ToList());
-            
+
             try
             {
                 return await ConcatAsync(inputFiles.Select(x => x.TempFileName));
@@ -170,14 +177,14 @@ public async Task<IPDFtkResult<byte[]>> ConcatAsync(IEnumerable<byte[]> pdfFiles
                 inputFiles.Dispose();
             }
         }
-        
+
         /// <inheritdoc/>
         public async Task<IPDFtkResult<byte[]>> ConcatAsync(IEnumerable<Stream> pdfFiles)
         {
             var inputFiles = await Task.WhenAll(
                 pdfFiles.Select(async file => await TempPDFtkFile.FromAsync(file))
                     .ToList());
-            
+
             try
             {
                 return await ConcatAsync(inputFiles.Select(x => x.TempFileName));
@@ -208,7 +215,7 @@ public async Task<IPDFtkResult<IEnumerable<byte[]>>> SplitAsync(byte[] pdfFile)
 
             return await SplitAsync(inputFile.TempFileName);
         }
-        
+
         /// <inheritdoc/>
         public async Task<IPDFtkResult<IEnumerable<byte[]>>> SplitAsync(Stream pdfFile)
         {
@@ -248,7 +255,7 @@ public async Task<IPDFtkResult<byte[]>> StampAsync(byte[] pdfFile, byte[] stampP
 
             return await StampAsync(inputFile.TempFileName, stampFile.TempFileName);
         }
-        
+
         /// <inheritdoc/>
         public async Task<IPDFtkResult<byte[]>> StampAsync(Stream pdfFile, Stream stampPdfFile)
         {
@@ -284,7 +291,7 @@ public async Task<IPDFtkResult<byte[]>> FillFormAsync(byte[] pdfFile,
                 flatten,
                 dropXfa);
         }
-        
+
         /// <inheritdoc/>
         public async Task<IPDFtkResult<byte[]>> FillFormAsync(Stream pdfFile,
             IReadOnlyDictionary<string, string> fieldData,

src/Kevsoft.PDFtk/PDFtkFileNotFoundExceptionException.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Kevsoft.PDFtk
+{
+    /// <summary>
+    /// Exception raised when the pdftk executable could not be found.
+    /// </summary>
+    [Serializable]
+    public class PDFtkFileNotFoundExceptionException : Exception
+    {
+        internal PDFtkFileNotFoundExceptionException(string[] searchedPaths)
+            : base(CreateMessage(searchedPaths))
+        {
+        }
+
+        private static string CreateMessage(string[] searchedPaths)
+        {
+            var message = "Could not find the pdftk executable, we tried the following paths:";
+            message += Environment.NewLine;
+            message += string.Join(Environment.NewLine, searchedPaths);
+            
+            return message;
+        }
+    }
+}

src/Kevsoft.PDFtk/PDFtkOptions.cs

@@ -0,0 +1,38 @@
+using System.Runtime.InteropServices;
+
+namespace Kevsoft.PDFtk
+{
+    /// <summary>
+    /// PDFtk Options
+    /// </summary>
+    public sealed class PDFtkOptions
+    {
+        /// <summary>
+        /// Initializes a new instance of the PDFtkOptions class.
+        /// </summary>
+        /// <param name="pdftkPath">The full path to the pdftk executable.</param>
+        public PDFtkOptions(string pdftkPath)
+        {
+            PDFtkPath = pdftkPath;
+        }
+
+        /// <summary>
+        /// The full path to the pdftk executable.
+        /// </summary>
+        public string PDFtkPath { get; }
+
+        /// <summary>
+        /// Creates the defaults for the PDFtk options.
+        /// </summary>
+        /// <returns></returns>
+        public static PDFtkOptions Default()
+        {
+            var fileName = RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
+                ? "pdftk.exe" : "pdftk";
+            
+            var pdftkPath = PathEnvironmentVariable.GetFileWithPath(fileName);
+
+            return new PDFtkOptions(pdftkPath);
+        }
+    }
+}

src/Kevsoft.PDFtk/PDFtkProcess.cs

@@ -7,13 +7,18 @@ namespace Kevsoft.PDFtk
 {
     internal sealed class PDFtkProcess
     {
+        private readonly PDFtkOptions _options;
+
+        public PDFtkProcess(PDFtkOptions options)
+            => _options = options;
+
         internal async Task<ExecutionResult> ExecuteAsync(params string[] args)
         {
             var process = new Process
             {
                 StartInfo = new ProcessStartInfo
                 {
-                    FileName = "pdftk",
+                    FileName = _options.PDFtkPath,
                     Arguments = string.Join(" ", args),
                     UseShellExecute = false,
                     RedirectStandardOutput = true,

src/Kevsoft.PDFtk/PathEnvironmentVariable.cs

@@ -0,0 +1,22 @@
+using System;
+using System.IO;
+
+namespace Kevsoft.PDFtk
+{
+    internal static class PathEnvironmentVariable
+    {
+        public static string GetFileWithPath(string fileName)
+        {
+            var pathEnvironmentVariable = Environment.GetEnvironmentVariable("PATH") ?? string.Empty;
+            var paths = pathEnvironmentVariable.Split(Path.PathSeparator);
+            foreach (var path in paths)
+            {
+                var fullPath = Path.Combine(path, fileName);
+                if (File.Exists(fullPath))
+                    return fullPath;
+            }
+
+            throw new PDFtkFileNotFoundExceptionException(paths);
+        }
+    }
+}