how to replace string in file using msbuild? - msbuild

Question

I want to replace a string such "how r u" in file test.xml with a string "i am fine" in another file xy.xml.using regular expression in ms build.
ie i have to read string from one file(xy.xml) and replace it in another file test.xml.
so please provide necessary steps to solve this issue with example

Answer 1

This is no longer required... you can now inject C# into the project/build file...
Define a custom task and parameters as follows:
<UsingTask TaskName="ReplaceFileText" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
<ParameterGroup>
<InputFilename ParameterType="System.String" Required="true" />
<OutputFilename ParameterType="System.String" Required="true" />
<MatchExpression ParameterType="System.String" Required="true" />
<ReplacementText ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Reference Include="System.Core" />
<Using Namespace="System" />
<Using Namespace="System.IO" />
<Using Namespace="System.Text.RegularExpressions" />
<Code Type="Fragment" Language="cs">
<![CDATA[
File.WriteAllText(
OutputFilename,
Regex.Replace(File.ReadAllText(InputFilename), MatchExpression, ReplacementText)
);
]]>
</Code>
</Task>
</UsingTask>
Then simply call it like any other MSBuild task
<Target Name="AfterBuild">
<ReplaceFileText
InputFilename="$(OutputPath)File.exe.config"
OutputFilename="$(OutputPath)File.exe.config"
MatchExpression="\$version\$"
ReplacementText="1.0.0.2" />
</Target>
The above example replaces "$version$" with "1.0.0.2" in the "File.exe.config" located in the output directory.

Answer 2

There is very simple approach to just replace string in a file:
<Target Name="Replace" AfterTargets="CoreCompile">
<PropertyGroup>
<InputFile>c:\input.txt</InputFile>
<OutputFile>c:\output.txt</OutputFile>
</PropertyGroup>
<WriteLinesToFile
File="$(OutputFile)"
Lines="$([System.IO.File]::ReadAllText($(InputFile)).Replace('from','to'))"
Overwrite="true"
Encoding="Unicode"/>
</Target>
See https://learn.microsoft.com/en-us/visualstudio/msbuild/property-functions?view=vs-2019
to explore inlinable C# code. [System.Text.RegularExpressions.Regex] included into the list.

Answer 3

The answer from #csharptest.net is good, but it doesn't work on DotNetCore. I would have added this as a comment, but I don't have enough reputation.
On DotNetCore you have to update:
Task Factory to "RoslynCodeTaskFactory"
Task Assembly to "$(MSBuildToolsPath)\Microsoft.Build.Tasks.Core.dll"
Remove the reference to "System.Core"
The consuming Target has to specify the "AfterTargets" attribute as "Build"
Everything else should be the same:
<Project Sdk="Microsoft.NET.Sdk.Web">
...
<UsingTask
TaskName="ReplaceFileText"
TaskFactory="RoslynCodeTaskFactory"
AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.Core.dll">
<ParameterGroup>
<InputFilename ParameterType="System.String" Required="true" />
<OutputFilename ParameterType="System.String" Required="true" />
<MatchExpression ParameterType="System.String" Required="true" />
<ReplacementText ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Using Namespace="System"/>
<Using Namespace="System.IO"/>
<Using Namespace="System.Text.RegularExpressions" />
<Code Type="Fragment" Language="cs">
<![CDATA[
File.WriteAllText(
OutputFilename,
Regex.Replace(File.ReadAllText(InputFilename), MatchExpression, ReplacementText)
);
]]>
</Code>
</Task>
</UsingTask>
<Target Name="AfterBuildStep" AfterTargets="Build">
<ReplaceFileText
InputFilename="$(OutputPath)File.exe.config"
OutputFilename="$(OutputPath)File.exe.config"
MatchExpression="\$version\$"
ReplacementText="1.0.0.2" />
</Target>
</Project>

Answer 4

EDIT: This answer is obsolete. Use solution below...
Use ReadLinesFromFile task to get replacement string from the xy.xml file. Check this
Then use value from xy.xml as a replacement string for FileUpdate task. Check this
And put it all together ;)

Answer 5

You can use the task FileUpdate from MSBuild Community Tasks as explained in the article
http://geekswithblogs.net/mnf/archive/2009/07/03/msbuild-task-to-replace-content-in-text-files.aspx

Answer 6

If you prefer not using third party (community) binaries, nor embedding code into your msbuild project, I'd suggest creating a simple task library which implements File.WriteAllText and can later host other tasks :
using System.IO;
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
public class FileWriteAllText : Task
{
[Required]
public string Path { get; set; }
[Required]
public string Contents { get; set; }
public override bool Execute()
{
File.WriteAllText(Path, Contents);
return true;
}
}
Then you can replace, append, etc. in msbuild :
<UsingTask TaskName="FileWriteAllText" AssemblyFile="MyTasks.dll" />
<FileWriteAllText Path="test.xml"
Contents="$([System.Text.RegularExpressions.Regex]::Replace(
$([System.IO.File]::ReadAllText('test.xml')), 'how r u', 'i am fine'))" />

Answer 7

I ran the both replacements against same file that sits on a Unix drive and used the unc path to it \server\path...:
<ReplaceFileText
InputFilename="$(fileToUpdate)"
OutputFilename="$(fileToUpdate)"
MatchExpression="15.0.0"
ReplacementText="15.3.1"/>
<FileUpdate Files="$(fileToUpdate2)"
Regex="15.0.0"
ReplacementText="15.3.1" />
and the cs custom action above does not add the bom; however the FileUpdate did:
%head -2 branding.h branding2.h
==> branding.h <==
#/* branding.h
#** This file captures common branding strings in a format usable by both sed and C-preprocessor.
==> branding2.h <==
#/* branding.h
#** This file captures common branding strings in a format usable by both sed and C-preprocessor.
Thanks csharptest.net - I was doing doing exec's with perl subtitute commands for unix builds.

Answer 8

An updated to answer from James
<UsingTask TaskName="ReplaceTextInFiles" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.$(VsBuildTaskBinarySuffix).dll">
<ParameterGroup>
<MatchExpression ParameterType="System.String" Required="true" />
<ReplacementExpression ParameterType="System.String" Required="true" />
<InputFile ParameterType="Microsoft.Build.Framework.ITaskItem" Required="true" />
<IsTextReplaced ParameterType="System.Boolean" Output="True"/>
</ParameterGroup>
<Task>
<Reference Include="System.Core" />
<Using Namespace="System" />
<Using Namespace="System.IO" />
<Using Namespace="System.Text.RegularExpressions" />
<Code Type="Fragment" Language="cs">
<![CDATA[
bool isMatchFound = false;
string filecontent = "";
string path = InputFile.ItemSpec;
Log.LogMessage(MessageImportance.High, "[ReplaceTextInFiles]: Match= " + MatchExpression);
Log.LogMessage(MessageImportance.High, "[ReplaceTextInFiles]: Replace= " + ReplacementExpression);
IsTextReplaced = false;
using(StreamReader rdr = new StreamReader(path))
{
filecontent = rdr.ReadToEnd();
if (Regex.Match(filecontent, MatchExpression).Success)
{
filecontent = Regex.Replace(filecontent, MatchExpression, ReplacementExpression);
isMatchFound = true;
}
}
if(isMatchFound){
using(StreamWriter wrtr = new StreamWriter(path))
{
wrtr.Write(filecontent);
IsTextReplaced = true;
Log.LogMessage(MessageImportance.Normal, "[ReplaceTextInFiles]: Replaced text in file:" + path);
}
}
]]>
</Code>
</Task>