1. MS QuickQ(j/k) a quick question
- Posted by Matt Z Nunyabidness <matt1421 at JUNO.COM>
Sep 22, 1998
-
Last edited Sep 23, 1998
I'm developing a program called PikX that's sorta like my camera.ex and
Ralf's txtshow.ex combined. Here's the syntax:
ex PikX s/l filename
s is for saving pictures, and l is for loading them. Just one problem. It
doesn't know you supplied a valid action. Here's the code:
PikX.ex:
include wildcard.e
include get.e
include graphics.e
include user.e
include image.e
object cl,fname,action,vc
sequence pic
integer fn
cl=command_line()
if length(cl)<4 then
puts(1,"\nUsage: ")
puts(1,"\nPikX s/l filename")
abort(0)
end if
action=cl[3]
fname=cl[4]
vc=video_config()
action=upper(action)
if atom(action)='S' then
pic=save_text_image({1,1},{vc[3],vc[4]})
puts(1,"\nOpening "&fname&"...")
fn=open(trim(fname),"w")
if fn=-1 then
puts(1,"\nThere was an error opening "&fname)
puts(1,"\nWhat might have occured is an access denied error")
abort(1)
end if
print(fn,pic)
close(fn)
abort(0)
elsif atom(action)='L' then
puts(1,"Attempting to read from "&fname&"...")
fn=open(fname,"r")
if fn=-1 then
puts(1,"\nThere was an error loading "&fname)
puts(1,"\nWhat might have occured is a file not found")
puts(1,"\nPlease check your typing and try again")
abort(2)
end if
pic=get(fn)
if pic=-1 then
if pic=GET_EOF then
puts(1,"Reached the end of "&fname&" too soon.")
abort(3)
elsif pic=GET_FAIL then
puts(1,fname&" does not contain a valid image.")
abort(4)
end if
end if
close(fn)
clear_screen()
display_text_image({1,1},pic[2])
if wait_key() then
end if
abort(0)
end if
puts(1,"\n"&action&": This is not a supported action")
Could y'all tell me what's wrong with it?
-------------------------------------
When it comes to programming languages, Euphoria is a cut above -
matt1278 at juno.com and matt1421 at juno.com(and soon to be
irisnmatt at prodigy.net. Then again, maybe not) Euphoria programmer
2. Re: MS QuickQ(j/k) a quick question
> if atom(action)=3D'S' then
I think you misunderstand the use of atom(). atom() gives you a boolean
telling you whether something is an atom. There is no need for type casting
in Euphoria. You should change this to:
if compare(action,"S") =3D 0 then
you could also use:
if action[1] =3D 'S' then
I recommend using the first one since it doesn't matter what action is.
Jeffrey Fielding
JJProg at cyberbury.net
3. Re: MS QuickQ(j/k) a quick question
Matt Z Nunyabidness wrote:
>I'm developing a program called PikX. Just one problem.
>It doesn't know you supplied a valid action.
change your code to read:
<snip>
action=cl[3]
fname=cl[4]
--let's say byebye before we do anything else
if not atom(action) then
puts(1,"\n"&action&": This is not a supported action")
abort(numberofyourchoosing)
end if
--let's not do any of this until we know action is valid
vc=video_config()
action=upper(action)
if action='S' then
--save file stuff snipped
elsif action='L' then
--load file stuff snipped
end if
--end of program
okay, now to say why yours didn't work.
your lines:
if atom(action)='L' then
elsif atom(action)='S' then
are the culprits.
atom() returns a true or false (1 or 0) if the
target is/isnt an atom.
so what did your lines do?
if atom(action)='L' then
becomes
if (true/false)='L' then
now the (true/false) would evaluate to true if you
entered "ex pikX l smily.bmp" as the command line
and it would evaluate to false if you entered
"ex pikX load smily.bmp" as the command line.
looking at this closer:
first case:"ex pikX l smily.bmp"
if atom(action)='L' then
--action is an atom,namely 'L', therefore
--atom(action) is true (1) and we get:
if 1 = 'L' then
--as the next test
of course the expression 1 = 'L' is FALSE,
so the if-then is NOT executed.
second case:"ex pikX load smily.bmp"
if atom(action)='L' then
--action is NOT an atom,namely "LOAD", therefore
--atom(action) is false (0) and we get:
if 0 = 'L' then
and of course the expression 0 = 'L' is ALSO FALSE
so the if-then cannot be executed again.
did this explanation help or hurt? ;)
also, matt, _please_ indent a bit... it *really* helps...
*alot*
use whatever indention style you like, even single
character indenting, as long as blocks line up.
you'll help us and perhaps even yourself...
hope this helps--Hawke'
4. Re: MS QuickQ(j/k) a quick question
k hawke. cyaz!
-------------------------------------
When it comes to programming languages, Euphoria is a cut above -
matt1278 at juno.com and matt1421 at juno.com(and soon to be
irisnmatt at prodigy.net. Then again, maybe not) Euphoria programmer
_____________________________________________________________________
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5. Re: MS QuickQ(j/k) a quick question
u gave me an idea. the bmp thing, so i added a bitmap action.
-------------------------------------
When it comes to programming languages, Euphoria is a cut above -
matt1278 at juno.com and matt1421 at juno.com(and soon to be
irisnmatt at prodigy.net. Then again, maybe not) Euphoria programmer
_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]
6. Re: MS QuickQ(j/k) a quick question
Error handling is for Beta-testers.
snortboy
