msh: Extract text from a stream with grep-string

One of the biggest missing functions in the command prompt is the ability to extract lines from a file that match a pattern. For UNIX users, the command grep is so often used that it has become a verb. The msh has a grep-string cmdlet that performs grep-like string parsing.

Use grep-string to search for a text pattern in a stream of text, for example:


will extract lines from the dir command output containing the text txt. For more information about the use of grep-string, use the help cmdlet:


Unfortunately, it appears that Microsoft used the name grep without really meaning it. Grep stands for global regular expression parser and its greatest strength is the 'regular expression' part. The msh grep-string doesn't use regular expressions. One promising thought is that since these are all defined cmdlets, someone adventurous could write a real grep function.