I want to know if there is a package to send a piece of text to shell commands like sed, awk or other text processing utilities and then get the result back to emacs? Thanks.
Possibly, but there's no need to install a package for this; it's built in.
shell-command-on-region (bound to
M-| by default) prompts for and then executes a shell command, sending it whatever you have selected on stdin, then displays the output in a temporary buffer. With a prefix arg (so
C-u M-|) it replaces the contents of the region with the output of the command.
There are other details in the documentation, so you might want to read it. Type
C-h f shell-command-on-region RET to open a help buffer for the command. This and other commands are also documented in the Emacs manual.
C-h i will open the info viewer with a list of all the available manuals. Select emacs, then navigate to section 40, Running Shell Commands from Emacs. You can jump right to it by typing
M-: (info "(emacs)Shell"), but that's a bit of a mouth-full.