Question

I’m trying to see if there is an entry for some input in a file, so I’m using a regular expression to query each line:

cat $file | where {$_ -match “^script\$fileName -*”}

where $fileName is some input defined elsewhere.

How do I alter the regex to interpolate the variable instead of matching for ‘$fileName’ ?

Answer 1

In addition to the answer given, as $fileName could contain characters such as ‘.’ or ‘\’ you should escape it as follows:

cat $file | where {$_ -match "^script\\$([regex]::Escape($fileName)) -*"}

The Escape method will escape bits like ‘.’ and ‘\’ for you.

E.g.

[regex]::Escape(".\bar.txt")

gives

\.\\bar\.txt