The regex pattern "^\d{3}-\d{3}-\d{4}$" matches a phone number in the format "123-456-7890".

Which option is used with grep to perform a case-insensitive search?

Which metacharacter is used to match the beginning of a line in regex?

What is the purpose of the sed command in Linux?

What does the regex pattern "\d{2,4}" match?

What does the regex pattern "[0-9]+" match?

How can you search for a specific word in a file using grep?

How can you search for a pattern in multiple files using grep (including subdirectories)?

Variables in PowerShell start with the $ symbol.