Re: [Ql-Users] Quanta Library Guide
Ah, seems I am wrong. If e.g. win1_mach_ ist not found, I think, TK2 searches for win1_win1_mach_. I use the following (extract from S_Edit ;-)): SV_BASE is my keyword to return the base of the system variables: 12480 DEFine FuNction file_test(name$) 12490 LOCal default 12495 REMark Read the length of DATAD$ 12500 default=PEEK_W(PEEK_L(SV_BASE+176)) 12506 REMark set the length of DATAD$ to zero, the string itself remains 12510 POKE_W PEEK_L(SV_BASE+176),0 12520 ferr=FOP_IN(#5,name$) 12530 CLOSE#5 12535 REMark restore the length of DATAD$ 12540 POKE_W PEEK_L(SV_BASE+176),default 12550 RETurn ferr 12560 END DEFine file_test I set the data_default to , so I really know, if the file exists or not. Cheers...Ralf - Original Message - From: Ralf Reköndt ralf.rekoe...@t-online.de To: ql-us...@q-v-d.com Sent: Saturday, April 21, 2012 6:50 PM Subject: Re: [Ql-Users] Quanta Library Guide The FOP_xxx functions (and all similar TK2 things) always tried to use the Data default next, if a direct call was unsuccessful. So, if I try to check Win1_test_, and it does not exist, Win1_ is checked next (if Data default), which is very likely to be successful. So you can't be sure, that the correct device was opened. That's why it is better, to set the Data default to , then try, then set it back to where it was before. - Original Message - From: Bob Spelten b...@upcmail.nl To: ql-us...@q-v-d.com Sent: Saturday, April 21, 2012 5:43 PM Subject: Re: [Ql-Users] Quanta Library Guide Op Sat, 21 Apr 2012 16:10:15 +0200 schreef Ralf Reköndt ralf.rekoe...@t-online.de: Hmm, but the TK2 Manual states about OPEN_DIR, so, apart from Level 2, it should be possible. But what kind of directory, if not Level 2? Perhaps just the root one. Section 10 Open and Close The standard QL channel OPEN commands are redefined by Toolkit II to use the data directory. In addition, Toolkit II provides a set of functions for opening files either using a specified channel number (as in the standard QL commands), or they will find and return a vacant channel number. The functions also allow filing system errors to be intercepted and processed by SuperBASIC programs. Commands OPEN #channel, nameopen a file for read/write OPEN_IN #channel, name open a file for input only OPEN_NEW #channel, nameopen a new file OPEN_OVER #channel, name open a new file, if it exists it is overwritten OPEN_DIR #channel, nameopen a directory CLOSE #channelsclose channels The problem is related to the FTEST command trying to open a file rather than a directory to verify its existance. In SMSQ/E a directory can be opened as a file, but in QDOS I don't think it can. The correct way to check for the validity of devices and directories would be to attempt to open a directory, not a file (TRAP#2 with D0=1 and D3=4 rather than D3=1). The Function FOP_DIR can be used but is not very reliable. I did a quick QDOS test on my demo Q-emuLator where win1_ is a W$ folder, win2_ is a QL floppy. chn= FOP_DIR (win1_): PRINT FTYP(#chn): produced 255. chn= FOP_DIR (win1_mach_): PRINT FTYP (#chn): also produced 255 while mach_ is part of a filename and not a directory! Even chn FOP_DIR (win1_ma): PRINT FTYP (#chn): returned as valid directory. This was not the case with win2_, there a FTYP returned zero for everything. But chn= FOP_DIR (usb1): opened a channel to win2_, PRINT FTYP(#chn): returned zero and DIR usb1_ gave the name of the floppy and the sector count. So this is here not a good level 1 test to see if a device or directory actually exists. Minerva gave the same results. Mind you, even under QPC2 I can happily FOP_OVER (a_file) to my win8_, which is a QXL.WIN on the cdrom! Bob -- The BSJR QL software site at: http://members.upc.nl/b.spelten/ql/ ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Raspberry Pi - starts
In message 4f92c11b.8080...@dunbar-it.co.uk, Norman Dunbar nor...@dunbar-it.co.uk writes Hi Bryan, On 21/04/12 10:21, Bryan Horstmann wrote: The only things I know about Python are from the Cheat Sheet I mentioned earlier. But where are the equivalent of all the many other S*BASIC Keywords? Python isn't S*Basic, so most of the well known and loved S*Basic commands and keywords etc will not be there. Norm. As Norman says ... it is not a BASIC, so not all the 'helpers' as 'keywords', like in S*BASIC Its antecedents are in C/C++, so it more open ended than a BASIC programming language. -- Malcolm Cadman ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Raspberry Pi - starts
In message 77845c9e-9410-4678-a5d7-ac1476607...@firshman.co.uk, Tony firshman t...@firshman.co.uk writes On 18 Apr 2012, at 17:31, Malcolm Cadman q...@mcad.demon.co.uk wrote: In message 4f8e8d97.7070...@newlan.org, Bryan Horstmann b...@newlan.org writes Hi Bryan, Thanks for the link. I believe that everything is covered within functions, yet I haven't programmed enough with Python to see if that is an advantage or a limitation. PS - You are not the Bryan, named in a Python film, are you? ... :-) Silly - that was 'Brian' (8-)# Tony (Looking on the bright side of life) Yes, yet he may have cunningly disguised himself, as Bryan, to fool his followers ... :-) -- Malcolm Cadman ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Raspberry Pi - starts
In message 4f927160.2090...@dunbar-it.co.uk, Norman Dunbar
nor...@dunbar-it.co.uk writes
Hi Norman,
Great ... :-) ... we need you to write an easy-peasy Guide to Python!
I have been experimenting with a rather 'old version' - 2.5.2 - dated at
2008, that I never quite got around to using before the Raspberry Pi
revival came along.
With the PC Windows version, there is a separate 'interpreter' window
that runs and compiles, as you say, much like a BASIC. Easy ... :-)
I have just updated to 3.7, on Windows, 32 bit version for my machines.
Morning all,
On 20/04/12 21:40, Dilwyn Jones wrote:
This all sounds very interesting and possibly a fairly straightforward
language for S*BASIC users to learn. I notice there's versions of Python
for Windows as well as Linux etc. Anyone know if a Python program
written on one platform such as Windows, be run on another such as
Linux?
Yes. There's a few ways to run a python program on Linux/Unix either by
telling the python interpreter the name of the file:
python filename.py
or by putting this as the first line in the program:
#!/usr/bin/env python
then making it executable:
chmod u+x filename.py
then simply calling it:
./filename.py
Under windows, only the first option is available and if the program
contains the #!/usr/bin/env python line, it gets treated as a comment
and completely ignored.
There's also a python interpreter which sits there and waits for you to
type something in, then compiles and executes it.
Guess if the programs are written and saved using a text editor
there's a chance this might be possible, although probably endian issues
might arise with numbers, for example?
There's no problem with endians or numbers etc, well, not those
problems anyway! There are gotchas to watch out for with numbers:
print 3 / 4
0
The '/' operator is equivalent to integer DIV. If you want to get a
floating point answer, you need to float one or both operands:
print float(3) / float(4)
0.75
or
print float(3) / 4
0.75
or, simply:
print 3 / 4.0
0.75
Python is pretty nifty in it's ability to coerce variables from one
type to another, so in the above, it sees one float argument and
coerces the int argument into float and gives back a float answer.
It doesn't coerce strings to floats, or ints:
print '313' + 300 + '13'
Traceback (most recent call last):
File pyshell#14, line 1, in module
print '313' + 300 + '13'
TypeError: cannot concatenate 'str' and 'int' objects
But you can do it implicitly:
print int('313') + 300 + int('13')
626
And not necesarily in base 10 either:
print int('313', 16) + 300 + int('13', 8)
1098
Which is obviously 787 + 300 + 11.
Admittedly I know nothing about Python (yet... - it looks interesting)
You may not know Python yet, but you are using it frequently! Calibre,
your most favourite program of recent times, is written in Python. So
you can see it's a capable programming language.
The use of indents in interesting. You do do this in Python:
#!/usr/bin/env python
Dilwyn = 'Jones'
Tony = 'Firshman'
Malcolm = 'Cadman'
if (Dilwyn == Tony):
print Tony and Dilwyn and the same person!
elif (Tony == Malcolm):
print Clones are people two!
else:
print Everyone is an individual.
The colons mark the start of a block, which must be indented (4 spaces
is the Python standard). The block ends when the indent comes back out.
Typing the file above using into vi was interesting as it understands
the indentation and did it for me automagically, probably based on the
file name (ql.py).
In case anyone is wondering, the else clause is executed.
Arrays are the usual stuff but are called lists:
ql_people = [Dilwyn, Tony, Marcel, Jochen, ]
To print them out, for example:
for person in ql_people:
print This person is: $s % person
They can also be dictionaries. These are like lists, but hava an access
key, and use different open/close brackets:
ql_people = {'Jones': 'Dilwyn', Firshman: Tony}
print ql_people['Jones']
Dilwyn
So, you could use a dictionary to define a record of some sort:
dj = {'name': 'Dilwyn Jones',
'age': 32,
'nationality': 'Welsh',
'lives in': 'Tal-y-Bont'}
print dj
{'nationality': 'Welsh', 'age': 32, 'name': 'Dilwyn Jones',
'lives in': 'Tal-y-Bont'}
print dj['lives in']
Tal-y-Bont
print dj['name'], dj['age']
Dilwyn Jones 32
You can even add functions to dictionaries. Then, a step up from
dictionaries is a class. But I'll not bother with that, I think I've
warbled on long enough!
For Python beginners there are a couple of decent books, one of which I
got free from Amazon for my Kindle:
Hello Python:
