regex - In sed, how to represent "alphanumeric or _ or -" -


tried

[a-za-z0-9-_] [a-za-z0-0\-\_] [[[:alnum:]]-_] ...

what correct way represent in regular expression?

it seems [a-za-z0-9-] works alphanumeric or dash. when add underscore, breaks.

that character class:

[[:alnum:]_-]

which means allow 1 of these:

1. alpha numeric 1. underscore 1. hyphen

it important keep hyphen @ 1st or last position in character class avoid escaping.


Comments

Post a Comment

Popular posts from this blog

Why can rails not find a route created by a helper? -

i created member route in rails 4: resources :line_items post 'decrement', on: :member end and gave matching method in line_items controller: def decrement @cart = current_cart @line_item = @cart.line_items.find_by_id(params[:id]) @line_item.decrement_quantity respond_to |format| if @line_item.save format.html { redirect_to shop_path, notice: 'line item updated.' } format.js {@current_item = @line_item} format.json { head :ok } else format.html { render action: "edit" } format.js {@current_item = @line_item} format.json { render json: @line_item.errors, status: :unprocessable_entity } end end end but when try make button: <%= button_to 'x', decrement_line_item_path(item) %> i error: no route matches [post] "/carts/25" what gives? your error message is: no route matches [post] "/carts/25" but expectin...
Read more

javascript - jquery or ashx not working -

i using ajax file upload control. it creating html: <form action="/pages/handlers/asyncfileuploadhandler.ashx" method="post" enctype="multipart/form-data" target="ajaxuploader-iframe-1397144545"> <input type="hidden" name="type" value="mindvoice"> <input type="file" id="imagefile" style="display: block; width: 80%; margin-right: auto; margin-left: auto;"> </form> and target is: <iframe width="0" height="0" style="display:none;" name="ajaxuploader-iframe-1397144545" id="ajaxuploader-iframe-1397144545"></iframe> the form submitted using .submit() . my ashx handler: <%@ webhandler language="c#" class="asyncfileuploadhandler" %> using system; using system.web; using nettpals.core; public class asyncfileuploadhandler : ihttphandler { public void processre...
Read more

opencv - DataType<cv::detail::deriv_type>::depth what is it used for -

i wondering why line used in lucas kanade tracker in opencv: datatype<cv::detail::deriv_type>::depth can explain me? in opencv, depth of mat refers type of data contained in mat 's data buffer. represented integer values correspond given data type. these integers commonly abstracted appropriate macro definition (e.g. uchar data represented macro cv_8u ). cv::datatype type-traits class provides method obtain corresponding integer value without having memorize macro means data type. there few cases user code needs use datatype::depth . more common datatype::type . a simple example shows 1 possible use of datatype::depth : cv::mat uchar_data = cv::mat::ones(3, 3, cv_8uc1); cv::mat float_data; uchar_data.convertto(float_data, cv::datatype<float>::depth); // ^^ equivalently replaced // cv_32f macro float_data.at<float>(0,1) += 0.5f; std::cout << float_data << std::endl;...
Read more