how to manipulate data like awk or perl when visiting a file

[reader]

I want to get a leg up on how I might manipulate a file like I can
with shell tools or awk/perl.

Examples:  I want to display only the first field of lines 30 thru 75
           I want to reverse field 1 and 5 and print those plus 6 of
           each line.
           I want to add up the numbers that appears in field 7 of
           lines 11 through 28 printing the total to ~/sumtot.txt

I'd like to see a few basic examples and maybe I'll be able to get the
idea enough to do some of that when I need to.

I don't really want to start way at the beginning of elisp to get
started.   I hoped maybe there are some examples like that available
in existing info documents.

I haven't noticed much talk here about those kinds of chores so maybe
elisp isn't a good choice for that?