How can I replace a string in a file?

Hi,
I have a batch file as below:

call "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\Tools\VsDevCmd.bat"
cd C:\AutomationTestSamples\AutomationTestSamples\bin\Debug
start cmd /k vstest.console.exe AutomationTestSamples.dll /Logger:trx;LogFileName=%1/UnitTest1.trx /testcasefilter:FullyQualifiedName~AutomationTestSamples.UnitTest1.trx

Open in new window

I want to read a batch file line by line and if the line contains "UnitTest1.trx",
I want to replace "/testcasefilter:FullyQualifiedName~AutomationTestSamples.UnitTest1" with "/test".

I tried the following code but when I opened the file nothing was replaced. Any idea please?

string[] str = File.ReadAllLines(@"C:\Test\test.bat");
            for (int i = 0; i < str.Length; i++)
            {
                if (str[i].Contains(trxName))
                {
                    str[i].Replace(str[i].Substring(str[i].IndexOf("/testcasefilter")), "/test");                    
                }
                
            }

Open in new window

.NET ProgrammingC#

Last Comment

Chinmay Patel

8/22/2022 - Mon

Chinmay Patel

11/8/2018

Hi Isabell,

In the code sample above you are just reading the file contents in an string array. You need to write back those lines to the file as well to get the desired results.

Also string.Replace https://docs.microsoft.com/en-us/dotnet/api/system.string.replace?redirectedfrom=MSDN&view=netframework-4.7.2#System_String_Replace_System_String_System_String_ returns a string value which you have to use. It does not actually replace/change the content of the string.

Regards,
Chinmay.

ASKER CERTIFIED SOLUTION

Chinmay Patel

11/8/2018

THIS SOLUTION ONLY AVAILABLE TO MEMBERS.

View this solution by signing up for a free trial.

Members can start a 7-Day free trial and enjoy unlimited access to the platform.

See Pricing Options

Start Free Trial

GET A PERSONALIZED SOLUTION

Ask your own question & get feedback from real experts

Find out why thousands trust the EE community with their toughest problems.

Isabell