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Sed. Save lines that are ending with specific file-type

I have a textfile and would like to save all lines that are ending with .m2 or .M2. I tried several ways including this here

D:\filetype\core\sed.exe -n -e "s/^\(.*\)\.M2//" D:\filetype\listfile\test.txt > D:\filetype\listfile\test2.txt

But as result i only get a emtpy textfile, so i guess something is wrong with my code.

The other way was

D:\filetype\core\sed.exe -n -e "^/\(.*)\/.M2\/" D:\filetype\listfile\test.txt > D:\filetype\listfile\test2.txt

But in this case i wasn't able to locate the source of the error

unknown command: `^'

Thanks if someone can see my fault.

Solution

  • You can use below sed command:

    sed -n -e '/\.[mM]2$/p' <file_name>

    This will print all the lines which have .m2 or .M2 at the end

    Now comming to issues with your commands. Your first command does:

    sed -n -e "s/^\(.*\)\.M2//"

    which is a search and replace command indiacated by s in the command. Syntax for this command is s/search_text/replace_text/. Now if you are look at your command carefully, you are searching for something and replacing it with nothing - as indicated by last // in your command - where replace_text is missing.

    Your second command does

    sed -n -e "^/\(.*)\/.M2\/"

    which is incorrect syntax. General syntax of a sed command is :

    sed -e 'line_range command'

    where line range - which is optional - can be line numbers like1, 5 , 2-5, or a regular expression like /[gG]/, /[gG][iIuU]rl/. If line_range is missing, the first letter in sed command should be a command. In your case: line_range is missing - which is fine syntax wise -, however the first letter is ^ - which is not a sed command - because of which you are getting syntax error.

    The command that I suggested is 

    sed -n -e '/\.[mM]2$/p'

    Here, line_range is the regular expression /\.[mM]2$/ - which says "any line which has .m2 or .M2 at the end", and command is p, which is the letter for print command.