regex - How to delete empty lines in a file by Emacs? -

in emacs, how remove empty lines (including tabs , spaces) in file ?

can m-x replace-regexp trick?

i can find empty lines regexp: ^[st]*$, don't know how replace deleting.

thanks!

^ , $ match starts , ends of lines, not actual end-of-line characters. have explicitly type newline in look replace it.

to accomplish goal, replace-regexp

^[[:space:]]*^j

with nil (empty text). come in ^j, first press command , q, command , j. in entry field, shows actual line change.

regex emacs str-replace

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