Yes, one of my best tools is a single text
file, FACTS.DAT, that I use to remember
essentially all little <i>facts</i>.<p>What is amazing is the combination of (i)
how simple the file is, (ii) how easy it
is to use, (iii) how little work it took
to start using it, and (iv) how useful it
is.<p>I maintain the file, add to it, search it,
extract from it with my favorite text
editor KEdit and some macros I wrote for
KEdit. A lot of (i) -- (iv) is due to the
good functionality of KEdit. E.g., KEdit
has some sweetheart text parsing tools.<p>KEdit is no joke: It is a PC version of
XEDIT written by an IBM guy, on his own
time, in Paris and quickly was an
important tool inside IBM. The macro
language for XEDIT was Rexx, and for
KEDIT, Kexx, a version of Rexx.<p>Kexx is no joke, e.g., offers decimal
integer arithmetic of 1000 digits. E.g.,
recently, as part of developing some notes
on calculus for my 9 year old nephew, as
at<p><a href="https://news.ycombinator.com/item?id=22179494" rel="nofollow">https://news.ycombinator.com/item?id=22179494</a><p>I used that long precision arithmetic and
Taylor series to find Euler's constant e,
the base of the natural logarithm, to 36
decimal digits:<p>e = 2.71828182845904523536028747135266250<p>I have a command line command FACTS that
looks for any executing instance of KEdit
that has that file open and (i) if there
is an instance then makes that instance
visible and at the top of the Z-order and
(ii) otherwise creates such an instance.<p>What does the file look like?<p>A recent entry is<p><pre><code> ========================================================================
:Created at. 10:12:19 on Saturday, February 8th, 2020.
:Keys. Internet DNS sinkhole C2
C:\Users\user1\data05\topics\tech\communications\internet\domain_name\domain_name.doc
</code></pre>
So, the file consists of a sequence of
<i>entries</i> where each entry starts with a
line of equal signs and has a time-date
stamp, some keywords, and the contents of
the entry.<p>For this sample entry, the next time I
want to know about <i>sinkholes</i> and <i>C2</i> I
can read the file with its tree name in
the contents of that entry -- the tree
name is for a file on one of my disks.<p>How big is the file FACTS.DAT?<p>I've been using such files for 20+ years.
The latest version started on<p>Friday, September 2nd, 2005<p>and now has 97,223 lines.<p>The file has 2,902,471 bytes and from the
rotating disk on my little HP laptop loads
right away.<p>The number of days from September 2nd,
2005 and today, February 8th, 2020, should
be 5272, courtesy of some little KEdit
macro language procedures I wrote for
converting to/from dates and days from the
start of the Gregorian calendar.<p>Having KEdit <i>select</i> all the lines full
of equal signs and then count those lines
I get 5073 entries in the file. So, that
is<p>5073 / 5272 = 0.962<p>entries per day.<p>So<p>97,223 / 5272 = 18<p>says that my average has been about 18
text lines a day.<p>The average number of lines per entry is<p>97,223 / 5073 = 19.2<p>and the averge number of bytes per entry
is<p>2,902,471 / 5073 = 572.1<p>Lesson: Can do a lot with a really simple
tool.