Amiga Computing - Commodore Is Awesome

Paul Overaa
starts work on
a date
stamping utility
Over the next two months I'm going to
turn the skeleton code provided on the
February coverdisk (or on our Web site)
^^^B into a utility that will run in Workbench
that can extract date stamps (in ASCII form) from
all files in a given directory. There are plenty of uses
for such a program but the one I have in mind is
one which will allow easy date stamping of Web
pages.
If, for example, you check out my corner of
Amiga Computing's Web site you will see all pages
have a last updated date stamp in them. These
dates are in fact generated automatically by a utility
currently written in C, but I thought a directly coded
680x0 version might be useful for the purposes of
this column because, once you've seen the ideas
involved, you'll realise that the same framework
can be used to create many other utilities.
The starting point for the discussions is the
DirHandler() routine whose main job at the
moment (if we disregard the temporary print/clear
name operations) is to copy the selected directory
name from the asl requester. Copying is usually
done so a selected filename can be added to a
directory to produce a complete path for the file.
For our current application however, being only
interested in drawer names, we can eliminate the
copying and use the asl requester's own directory
buffer. This approach involves some minor changes
in that the text pointers of the intuiText structures
cannot now be defined using the original static
dimame reference.
Instead we install the pointers at run time (after
the internal asi buffers have been allocated). The
new method, which you'll find in my AllocFileReqO
routine, is to load aO with the asl requester base
and load ai with each IntuiText base in turn to
copy the pointers using indirect addressing instruc
tions like this:
■0«.l frJrauer(aO),it_lTeJt(a1)
These and a few other minor alterations - such as
adding an image to the display using the Intuition
Drawlmage() function and changing the window
and menu text - will be easy enough to recognise
by comparing this month's source with that from
the previous issue. The real work however, involves
extending the DirHandlerO routine so it can search
the named directory and locate any files present.
Dos Operations
Once a directory name is available the directory
must be locked using the Dos library LockO func
tion. An FIB (File Info Block) must also be allocated
using AlIocDosObject() and it's initial directory val
ues set by calling Examine(). An ExNextO loop can
then be used to examine all the files in the select
ed directory.
The easiest way to explain the relationship
Amiga Computing
MARCH 1997
DirHandler
.deallocate
.t»it
rts
StampOnIT!
movem.l
lea
tfO-d5/iO-a2/a5,-