OT: (or is it) seeking app for a single file content search

[joe at actionline.com]

For many years, I have maintained a simple text file list of contact
names, phone numbers, addresses, and other miscellaneous information
-- a single line for each entry. That file now has more than 3,000
names and phone numbers.

To find/retrieve a phone number, I have used a simple shell script
with grep. While this has worked fine from the Linux command line,
and it gives instantaneous results, I have often wondered and
sometimes searched for a utility app that could do the same thing.

I do not want a multiple function contact and calendar app, but I
would like something with a *very simple* gui that I could access
from an icon on the desktop or panel; and I'd also like something
that would work on both my Linux boxes and also for my wife on her
windblows laptop.

The way my old shell script works is I just type: phone <E> on the
command line, and then press <S> for select, enter the name or part
of a phone number, and all entries that match the select criteria
display.  With the current method, I open the file in a text editor
to add new entries or make changes. But it would be nice to have the
option to press <A> to append a new, one-line text entry.  Leave it
to the user to make the entry in the same format as the rest of the
text file.

Anyone know of an existing *simple* app or utility that can do this
on both Linux and windblow?

Below a sample of the way my text file looks now when I search for
"library":

(Yes, I know the area code following the phone number is a bit
strange, but this goes waaaay back to when I first used this for
just a few dozen local phone numbers; and for a number of practical
reasons, I have opted to not reformat the entire text file.)

644-3300 #480 Mesa Express Library PO Box 1466 Mesa 95211
644-3182 #480 Mesa Library or 3184 or reference desk 3164
644-3569 #480 Mesa Library Brynn Burton, Suprv Librarian
644-2207 #480 Mesa Library main branch
262-4636 #602 PhoenixPublicLibrary.org -or- phxlib.org
644-2472 #480 Mesa Library Technology
644-2732 #480 Mesa Library Interlibrary Loan office
644-3182 #480 MesaLibrary.org
707-2100 #202 Library of Congress info
386-4648 #206 Seattle Library directory info center
543-0741 #206 University of Washington Engineering Library
651-7072 #360 Sno-Isle Library