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Diffstat (limited to 'upstream/Replace.cs')
| -rw-r--r-- | upstream/Replace.cs | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/upstream/Replace.cs b/upstream/Replace.cs new file mode 100644 index 0000000..3475a47 --- /dev/null +++ b/upstream/Replace.cs @@ -0,0 +1,223 @@ +/* +** 2016 February 26 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** This file contains C# code to perform regular expression replacements +** using the standard input and output channels. +*/ + +using System; +using System.Diagnostics; +using System.IO; +using System.Reflection; +using System.Runtime.InteropServices; +using System.Text.RegularExpressions; + +/////////////////////////////////////////////////////////////////////////////// + +#region Assembly Metadata +[assembly: AssemblyTitle("Replace Tool")] +[assembly: AssemblyDescription("Replace text using standard input/output.")] +[assembly: AssemblyCompany("SQLite Development Team")] +[assembly: AssemblyProduct("SQLite")] +[assembly: AssemblyCopyright("Public Domain")] +[assembly: ComVisible(false)] +[assembly: Guid("95a0513f-8863-48cd-a76f-cb80868cb578")] +[assembly: AssemblyVersion("1.0.*")] + +#if DEBUG +[assembly: AssemblyConfiguration("Debug")] +#else +[assembly: AssemblyConfiguration("Release")] +#endif +#endregion + +/////////////////////////////////////////////////////////////////////////////// + +namespace Replace +{ + /// <summary> + /// This enumeration is used to represent all the possible exit codes from + /// this tool. + /// </summary> + internal enum ExitCode + { + /// <summary> + /// The file download was a success. + /// </summary> + Success = 0, + + /// <summary> + /// The command line arguments are missing (i.e. null). Generally, + /// this should not happen. + /// </summary> + MissingArgs = 1, + + /// <summary> + /// The wrong number of command line arguments was supplied. + /// </summary> + WrongNumArgs = 2, + + /// <summary> + /// The "matchingOnly" flag could not be converted to a value of the + /// <see cref="Boolean"/> type. + /// </summary> + BadMatchingOnlyFlag = 3, + + /// <summary> + /// An exception was caught in <see cref="Main" />. Generally, this + /// should not happen. + /// </summary> + Exception = 4 + } + + /////////////////////////////////////////////////////////////////////////// + + internal static class Replace + { + #region Private Support Methods + /// <summary> + /// This method displays an error message to the console and/or + /// displays the command line usage information for this tool. + /// </summary> + /// <param name="message"> + /// The error message to display, if any. + /// </param> + /// <param name="usage"> + /// Non-zero to display the command line usage information. + /// </param> + private static void Error( + string message, + bool usage + ) + { + if (message != null) + Console.WriteLine(message); + + string fileName = Path.GetFileName( + Process.GetCurrentProcess().MainModule.FileName); + + Console.WriteLine(String.Format( + "usage: {0} <regExPattern> <regExSubSpec> <matchingOnly>", + fileName)); + } + #endregion + + /////////////////////////////////////////////////////////////////////// + + #region Program Entry Point + /// <summary> + /// This is the entry-point for this tool. It handles processing the + /// command line arguments, reading from the standard input channel, + /// replacing any matching lines of text, and writing to the standard + /// output channel. + /// </summary> + /// <param name="args"> + /// The command line arguments. + /// </param> + /// <returns> + /// Zero upon success; non-zero on failure. This will be one of the + /// values from the <see cref="ExitCode" /> enumeration. + /// </returns> + private static int Main( + string[] args + ) + { + // + // NOTE: Sanity check the command line arguments. + // + if (args == null) + { + Error(null, true); + return (int)ExitCode.MissingArgs; + } + + if (args.Length != 3) + { + Error(null, true); + return (int)ExitCode.WrongNumArgs; + } + + try + { + // + // NOTE: Create a regular expression from the first command + // line argument. Then, grab the replacement string, + // which is the second argument. + // + Regex regEx = new Regex(args[0]); + string replacement = args[1]; + + // + // NOTE: Attempt to convert the third argument to a boolean. + // + bool matchingOnly; + + if (!bool.TryParse(args[2], out matchingOnly)) + { + Error(null, true); + return (int)ExitCode.BadMatchingOnlyFlag; + } + + // + // NOTE: Grab the standard input and output channels from the + // console. + // + TextReader inputTextReader = Console.In; + TextWriter outputTextWriter = Console.Out; + + // + // NOTE: Loop until end-of-file is hit on the standard input + // stream. + // + while (true) + { + // + // NOTE: Read a line from the standard input channel. If + // null is returned here, there is no more input and + // we are done. + // + string inputLine = inputTextReader.ReadLine(); + + if (inputLine == null) + break; + + // + // NOTE: Perform regular expression replacements on this + // line, if any. Then, write the modified line to + // the standard output channel. + // + string outputLine = regEx.Replace(inputLine, replacement); + + if (!matchingOnly || !String.Equals( + inputLine, outputLine, StringComparison.Ordinal)) + { + outputTextWriter.WriteLine(outputLine); + } + } + + // + // NOTE: At this point, everything has succeeded. + // + return (int)ExitCode.Success; + } + catch (Exception e) + { + // + // NOTE: An exception was caught. Report it via the console + // and return failure. + // + Error(e.ToString(), false); + return (int)ExitCode.Exception; + } + } + #endregion + } +} |