How do I output lines that do not match 'this_string' using Get-Content and Select-String in PowerShell?

Question

I found a post about users that wanted to use grep in PowerShell. For example,

PS> Get-Content file_to_grep | Select-String "the_thing_to_grep_for"

How do I output lines that are NOT this_string?

Answer 1

Select-String has the NotMatch parameter.

get-content file_to_grep | select-string -notmatch "the_thing_to_grep_for"

Answer 2

get-content file_to_grep | select-string "^(?!the_thing_to_grep_for$)"

will return the lines that are different from the_thing_to_grep_for.

get-content file_to_grep | select-string "^(?!.*the_thing_to_grep_for)"

will return the lines that don't contain the_thing_to_grep_for.

Answer 3

gc  file_to_grep | ? {!$_.Contains("the_thing_to_grep_for")}

which is case-sensitive comparison by the way.