what is

echo $PWD | sed 's?.*users/[^/]\+/??'

Here PWD is path :


what exactly sed command is doing here and how s?.*users/[^/]\+/?? this will work ?

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s?.*users/[^/]\+/?? breaks down as follows:

  • s is the command of substitution
  • ? (all three of them) are expression separators (so the above might look like this as well: s@.*users/[^/]\+/@@). The general form is this: s/<match pattern>/<replacement>/<modifiers>. In this case there are no modifiers and no replacement in this substitution, so whatever is found by the first pattern will be removed from the stream.
  • .*users/[^/]\+/ is the search pattern and means:

    • .*whatever precedes users/
    • [^/]\+/ followed by something that's not \ (at least one such thing, possibly more) and these followed by one /.

    So it's targeting a string in a path that begins with users and is followed by one subfolder, eg. /subfolder/.

And thus what's left is this:


And here's the deleted part:


/proj/SAM1/ preceded users/ and then followed ssudi.

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