reorganized.

Console/FileOps.cs

@@ -0,0 +1,87 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace LargeFileSplitter
+{
+    public class FileOps
+    {
+        public int NumFilesCreated { get; set; }
+        private IEnumerable<string> AllLinesToWrite { get; set; }
+        SplitJob Job { get; set; }
+        /// <summary>
+        /// Read the source file and split into 
+        /// </summary>
+        /// <param name="job"></param>
+
+        public FileOps(SplitJob job)
+        {
+            this.Job = job;
+            AllLinesToWrite = ReadFile(Job.FileToSplit);
+            Job.TotalLines = AllLinesToWrite.Count();
+        }
+        public void SplitFile()
+        {
+            var sw = Stopwatch.StartNew();
+
+            if (AllLinesToWrite.Any() == false) return;
+
+            WriteFiles();
+            sw.Stop();
+            Console.WriteLine("Time Spent (s): " + sw.Elapsed.TotalSeconds.ToString());
+        }
+
+        /// <summary>
+        /// Read the contents of the file from disk.
+        /// </summary>
+        /// <param name="filePath"></param>
+        /// <returns></returns>
+        public IEnumerable<string> ReadFile(string filePath)
+        {
+            try
+            {
+                return File.ReadLines(filePath).ToList();
+            }
+            catch (System.OutOfMemoryException)
+            {
+                Console.WriteLine("We encountered an OutOfMemoryException. Switching to a slower method of splitting.");
+                return File.ReadLines(filePath);
+            }
+        }
+
+
+        /// <summary>
+        /// Given the large collection of strings read from disk, split into the appropriate number of files. If the source file is empty, tilt immediately.
+        /// </summary>                
+        public void WriteFiles()
+        {
+            if (AllLinesToWrite.Any() == false) return;
+            string header = AllLinesToWrite.First();
+            foreach (int i in Enumerable.Range(1, Job.NumFilesToCreate))
+            {
+                FileInfo baseFile = new FileInfo(Job.FileToSplit);
+                string newFile = Path.Combine(baseFile.DirectoryName, string.Format("{0}-{1}", i, baseFile.Name));
+
+                //always skip the header, the batches previously taken + 1 for the header.
+                //First iteration, skip none.
+                int skip = ((i-1) * Job.LinesPerFile + 1);
+
+                List<string> newFileContents = AllLinesToWrite.Skip(skip).Take(Job.LinesPerFile).ToList();
+
+                //write the file when there are new contents to be written. we may have the case where we don't need to create empty files if the user
+                //has specified more files than we need.
+                if (newFileContents.Any())
+                {
+                    newFileContents.Insert(0, header);
+                    File.WriteAllLines(newFile, newFileContents);
+                    NumFilesCreated++;
+                }
+            }
+        }
+
+    }
+}

Console/LargeFileSplitter.csproj

@@ -0,0 +1,57 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{93322CCA-D6F7-4F88-91E5-6FE42DC3131A}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>LargeFileSplitter</RootNamespace>
+    <AssemblyName>LargeFileSplitter</AssemblyName>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="FileOps.cs" />
+    <Compile Include="SplitJob.cs" />
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

Console/Properties/AssemblyInfo.cs

@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("LargeFileSplitter")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("LargeFileSplitter")]
+[assembly: AssemblyCopyright("Copyright ©  2014")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("1c2c5879-e40d-4b54-bd63-94adad84f609")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

Console/SplitJob.cs

@@ -0,0 +1,25 @@
+using System;
+namespace LargeFileSplitter
+{
+    public class SplitJob
+    {
+        /// <summary>
+        /// The user's choice for the max number of files to create.
+        /// </summary>
+        public int NumFilesToCreate { get; set; }
+        /// <summary>
+        /// The large file on disk to be split.
+        /// </summary>
+        public string FileToSplit { get; set; }
+
+        /// <summary>
+        /// A calculated value determining how many lines per file. It's approximately TotalLines/NumFilesToCreate with rounding up to avoid situations where lines are missed.
+        /// </summary>
+        public int LinesPerFile { get { return Convert.ToInt32(Math.Ceiling((this.TotalLines / this.NumFilesToCreate))); } } //Ceiling to avoid missing fractions of lines
+
+        /// <summary>
+        /// The number of lines that the large file contains.
+        /// </summary>
+        public decimal TotalLines { get; set; }
+    }
+}

LargeFileSplitter.sln

@@ -3,7 +3,7 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 2013
 VisualStudioVersion = 12.0.30110.0
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LargeFileSplitter", "LargeFileSplitter.csproj", "{93322CCA-D6F7-4F88-91E5-6FE42DC3131A}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LargeFileSplitter", "Console\LargeFileSplitter.csproj", "{93322CCA-D6F7-4F88-91E5-6FE42DC3131A}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution