.INTRODUCTION: 4 - The 3-Minute Introducton to Fdate
.ALIAS.......: 3-minute_intro
This is a "quick start" introduction to using Fdate.
INTRODUCTION: WHAT IS FDATE?
============================
Fdate is a utility for doing date formatting and date arithmetic in DOS
batch files. At least, that was its original purpose. Over the years,
functions were added to Fdate to support activities that people often
need to do in conjunction with working with dates.
To help you get started using Fdate, I've created this short
introduction which shows how to use Fdate to do the things most
users want to do. When you've finished, you may still have a
question: "Can I do such-and- such with Fdate?" If it involves
dates, it probably CAN be done with Fdate, although tricky things
are of course tricky to do, even with Fdate. A good next step
would be to look at the list of examples. With luck, you will
find an example that shows Fdate doing just what you want to do.
To understand how Fdate is working in a particular example, look
up the parameters used in the example.
see OVERVIEW Examples
THE 3-MINUTE INTRODUCTION TO FDATE
==================================
By far the most popular use of Fdate is to put today's date-- in a
particular format-- into an environment variable. Once this has been done,
the environment variable can be used and manipulated in many ways in a
batch file. Here are a few short exercises that will help you to learn how
to use Fdate's most basic features to do that.
1.
At the DOS prompt, type:
This will show you Fdate's HELP screens. Press ENTER to page through
the HELP screens.
The information on these HELP screens is very dense. It won't teach you
how to use Fdate, but it is useful for jogging your memory as you become
familiar with Fdate's various features.
2.
At the DOS prompt, type:
I've used lowercase "f" here to distinguish the value of the parameter
from the parameter-letter itself, but it really doesn't matter whether
the parameter or its value is in upper or lower case. Except for the /K
parameter (one of Fdate's advanced features), Fdate's parameters are not
case sensitive.
Here, the value of the "/F" (function) parameter is "f" (format a date).
The "/Ff" parameter tells Fdate that the function you want it to perform
is to format a date. Since the default date is "today", this command
will cause Fdate to display today's date on your screen in Fdate's
default output format.
3.
At the DOS prompt, type:
This command is just like the one in the previous example, except that
we've specified the "prefix parameter" (/P), which tells Fdate to add a
string to the beginning of its output. (There is also a "suffix
parameter" that tells Fdate to add a string to the end of its output.)
Note that the value of the /P parameter is enclosed in quotes. (Either
single quotes or double quotes will work.) We've had to enclose the
value in quotes because it contains embedded blanks (one blank after the
word "today" and another after the word "is").
4.
At the DOS prompt, type:
(Or you can put the same statement in a batch file.)
Here, you are telling Fdate to put out today's date in a specific
format. On the "output format" parm (/O) you are specifying that you
want the day in "ccyymmdd" format: two digits each for century, year-
within-century, month, day-of-month.
Note that the /O parm is a predefined, fixed, format. Fdate supports many
such pre-defined output formats. If you want more flexibility, then you can
"roll your own" date format using the /C (custom output) parameter.
5.
At the DOS prompt, type:
- FDATE /Ff /C"$Today is $N $d, $Y"
Here, you are telling Fdate to put out a string that you have
formatted. The /C parm tells Fdate that the output will be a
customized format. The string after the /C is enclosed in
quotes, because it contains blanks. The first character inside
the string is a $ -- this tells Fdate that you will be using the
$ as the escape charater. The symbols $M, $d, and $Y have
special meaning. (Note that, unlike most of Fdate's parameters,
these special symbols ARE case-sensitive.) For more
information,
see PARAMETER /C - Custom Output Date Formats
6.
At the DOS prompt, type:
- FDATE /Ff /Occyymmdd /p"@set date1=" >junk.bat
(Or you can put the same statement in a batch file.)
Here, you are telling Fdate to put out today's date in "ccyymmdd"
format. Because you are specifying the redirection symbol (>) and
a batch file name, Fdate's output is being redirected to the batch file.
You can look at the batch file by using the DOS "type" command:
Now you can run the batch file by typing
at the DOS command prompt.
This will cause JUNK.BAT to run and to put today's date in the DATE1
environment variable. If you type "SET" at the DOS prompt, and if
today is February 1, 1995, you will see as the last line of the SET
output:
7.
Use your favorite text editor to create a batch file called TEST.BAT.
In TEST.BAT, put the following lines:
.EXAMPLE:
@echo off
FDATE /Ff /p"@set date1=" >junk.bat
call junk.bat
del junk.bat
echo Today's date is: %date1%
set date1=
Note that in this example we have not specified an output format at all, so
Fdate will use its defaul format.
Here is the same batch file, with some commentary:
.EXAMPLE:
@echo off *** turn ECHO off, so the batch file executes quietly
FDATE /Ff /p"@set date1=" >junk.bat *** you know what this does
call junk.bat *** call junk.bat to set the date1 environment variable
del junk.bat *** cleanup -- delete junk.bat
echo Today's date is: %date1% *** use the environment variable
set date1= *** cleanup -- delete date1
8.
At this point, you know everything you need to know to put today's date
into an environment variable, which you can then use for whatever you
want. As the last step in this introduction, here's an example in which
you are copying a file (BACKUP.LOG, which is put out by a backup
program) to a file whose name contains today's date.
.EXAMPLE:
FDATE /Ff /Occyymmdd /Vdate1
copy BACKUP.LOG %date1%.LOG
WHAT TO DO NEXT?
================
Now that you know the basics, you may have everything you need to know in
order to use FDATE to satisfy your basic date-handling needs. If you need
more information, or are feeling adventurous, your next step should be to
explore the Fdate documentation, which discusses many more features of FDATE.
One of the most useful parts of the documentation is the list of
examples. Browse through the titles of the examples, to get a feel for
what is there.
see OVERVIEW Examples
Then look at the examples themselves. Many are quite elaborate (which
is natural, since they are there to show you how to do Hard Stuff).
Most of the examples are self-contained and ready-to-run -- if you copy the
text of the example into a batch file, the example code will run and do
what the title says it will do. I suggest you try one or two
of the examples that seem most interesting to you.
After the examples, the most useful parts of the Fdate documentation are
the sections documenting Fdate's various functions (the functions that
you can specify on the function parm, /F) and its various output
formats. I suggest you scan those sections, just to get a quick feel
for what's available to you.
Good Luck!
Steve Ferg