Use Regular Expression to find text within a pattern

Powershell regex might be disturbing because of multiple way to deal with escape characters :

So as you nested your string beetween simple quote :

• Groups can be marked with bracket or not : (.n) or .n
• Double quotes can be considered as standard characters
• Brackets can be considered as standard characters

If you nested your string beetween double quote, the double quote inside the string must be escape with standard powershell escape character : `"

So all following examples return the same result

$pattern = 'AssemblyCopyright("what ever in there")]'

# standard regex
$pattern -replace 'AssemblyCopyright\(\"(.*)\"\)\]', 'AssemblyCopyright("new pattern")]'
# no quote escape
$pattern -replace 'AssemblyCopyright\("(.*)"\)\]', 'AssemblyCopyright("new pattern")]'
# no brackets escape
$pattern -replace 'AssemblyCopyright\("(.*)"\)]', 'AssemblyCopyright("new pattern")]'
# no parenthesis to define group
$pattern -replace 'AssemblyCopyright\(".*"\)]', 'AssemblyCopyright("new pattern")]'
# double quote instead of simple quote
$pattern -replace "AssemblyCopyright\(`".*`"\)]", "AssemblyCopyright(`"new pattern`")]"

An example with more advanced regular-expression techniques:

> 'AssemblyCopyright("foo bar")]' -replace '(?<=AssemblyCopyright\(")[^"]*', 'bar'
AssemblyCopyright("bar")]

• (?<=AssemblyCopyright\(") is a lookbehind assertion that matches the specified subexpression, but doesn't make it part of the match (what is captured and, in this case, replaced).

• Since the lookbehind assertion found everything up to and including the opening " of the attribute, all we need is to match up to but excluding the next " ([^"]*) to fully match only the contents of the double-quoted string (the attribute value).

• Thus, we only need to specify the attribute value as the replacement string (sans quoting).