Question

I’m trying to replace a single character in a large string (textfile) using C#.
this string contain multiple lines of code.

At some point a batch file is called assigning multiple parameters:

  call c:\script.bat 1 1 16 localhost 1 1 %0%

It must become:

  call c:\script.bat 2 1 16 localhost 1 1 %0%

I’ve created the following statement to replace the regex dot group (in this case the first):

Regex.Replace(content, @"call c:\script.bat )(.)( 1 16 localhost 1 )(.)(%0%)","$1.$3$4$5")

Somehow I’m sure, replacing the number 1 that is in place of the match can’t be replaced with a 2 because then the replace string wil acces the non existing group 12 instead of group 1 with the character 2 attached to it.

Can someone give me a clue?

Answer 1

The simple solution would be to not capture the delimiting spaces:

Regex.Replace(content, @"(call c:\script.bat) \d (1 16 localhost 1 )(.)(%0%)","$1 2 $3$4$5")

Note: I’ve also used the \d digit character set. You may want to change this to \d+ for numbers larger than a single digit.