1. Deleting a file
Hi, I've got a problem:
I need to delete a file, but don't want to use the system() function,
cause it has to be "transparent" to the user. So I got this bright
idea of using DOS interrupts (#21). At the end is the code I used, but
it doesn't work... I keep getting DOS error 2 (file not found) and
5 (access denied). Can anyone tell me what is wrong? Is there any
other way to that?
I also needed to copy a file but I solve that with a loop of getc() and
puts() until an EOF.. is there another eficient way?
Thanks.
-------------CUT HERE--------------
-- SYS_DEL()
-- Uses DOS INT #21, service #41 to delete a file given an ASCIIZ filename
-- Returns 1 if succesfull, else return 0 and displays DOS error code
-- INT reference: HelpPC 2.1
function sys_del(sequence filename)
sequence reg_list
integer buff
buff = allocate_low(length(filename)+1)
poke(buff,filename)
poke(buff+length(filename),0)
reg_list = repeat(0,10)
reg_list[REG_AX] = #4100
reg_list[REG_DS] = floor(buff/16)
reg_list[REG_DX] = remainder(buff,16)
reg_list = dos_interrupt(#21,reg_list)
free_low(buff)
if remainder(reg_list[REG_FLAGS],2) != 0 then
puts(1, "DOS error number :")
print(1,reg_list[REG_AX])
puts(1,"\n")
return 0
else
return 1
end if
end function
--------END OF CODE--------
--
************************************
This message sent by Daniel Berstein
************************************
email: architek at geocities.com
homepages: http://www.geocities.com/SiliconValley/Heights/9316
http://www.cybercity.hko.net/silicon_valley/architek
2. Re: Deleting a file
On Mon, 28 Apr 1997 19:09:12 -0400 Architek <architek at GEOCITIES.COM>
writes:
>
>Hi, I've got a problem:
>I need to delete a file, but don't want to use the system() function,
>cause it has to be "transparent" to the user.
>
> ************************************
> This message sent by Daniel Berstein
> ************************************
> email: architek at geocities.com
If you are doing it from text mode then you can make your active
page, 1 or 2 or something other than your display page which
I believe is 0 by default. ONLY problem there is that I believe
your error message will pop up on page 0. NOT sure.
Check it out. You should have no problem using this with DOS
commands such as copy.
I am under ver 6.22 of DOS. My del doesn't return anything.
unless the file isn't found.
You should use:
file = "filename.tmp"
system("del "& file, 2)
OR
system("del filename.tmp", 2)
Since delete doesn't display anything you
can do it under Text or Graphics mode.
Hope this helps
--Lucius Lamar Hilley III
-- E-mail at luciuslhilleyiii at juno.com
-- I support transferring of files less than 60K.
-- I can Decode both UU and Base64 format.
3. Re: Deleting a file
Architek wrote:
I tested your function and got an dosserror 3. It meant that is could
not find the path. So I tried it with a path and my file was deleted.
Marcel Kollenaar
--Code --
include machine.e
-- SYS_DEL()
-- Uses DOS INT #21, service #41 to delete a file given an ASCIIZ
filename
-- Returns 1 if succesfull, else return 0 and displays DOS error code
with trace
-- INT reference: HelpPC 2.1
function sys_del(sequence filename)
sequence reg_list
integer buff
buff = allocate_low(length(filename)+1)
poke(buff,filename)
poke(buff+length(filename),0)
reg_list = repeat(0,10)
reg_list[REG_AX] = #4100
reg_list[REG_DS] = floor(buff/16)
reg_list[REG_DX] = remainder(buff,16)
reg_list = dos_interrupt(#21,reg_list)
free_low(buff)
if remainder(reg_list[REG_FLAGS],2) != 0 then
puts(1, "DOS error number :")
print(1,reg_list[REG_AX])
puts(1,"\n")
return 0
else
return 1
end if
end function
trace(1)
integer a
a = sys_del("c:\\euphoria\\pex\\test.asc")
4. Re: Deleting a file
Architek writes:
-- snip -----
buff = allocate_low(length(filename)+1)
poke(buff,filename)
poke(buff+length(filename),0)
--------------------------------------------------------
I was wondering if the last line should not read:
poke(buff + length(filename) + 1, 0)
^^^^
Am I right or am I right?
Hope this helps
Ad Rienks
5. Re: Deleting a file
- Posted by Architek <architek at GEOCITIES.COM>
Apr 30, 1997
-
Last edited May 01, 1997
Ad Rienks wrote:
> -- snip -----
> buff = allocate_low(length(filename)+1)
> poke(buff,filename)
> poke(buff+length(filename),0)
> --------------------------------------------------------
>
> I was wondering if the last line should not read:
> poke(buff + length(filename) + 1, 0)
> ^^^^
> Am I right or am I right?
I don't thinks so... give them numbers:
filename = "myfile" (length = 6)
bytes allocated: 6 + 1 = 7 bytes (lets give buff any address: 10 to 16)
poke(10,"myfile") ---> pokes bytes 10,11,12,13,14,15
poke(10+6,0) = poke(16,0) --> Which is defenitly the right offset of buff
I don't know if you understand my demostration, but if you didn't... the
original way is right, you must understand that offsets start from '0'.
Thanks anyway,
--
************************************
This message sent by Daniel Berstein
************************************
email: architek at geocities.com
homepages: http://www.geocities.com/SiliconValley/Heights/9316
http://www.cybercity.hko.net/silicon_valley/architek
6. Re: Deleting a file
- Posted by Jacques Deschenes <desja at QUEBECTEL.COM>
Apr 30, 1997
-
Last edited May 01, 1997
--=====================_862467637==_
At 19:09 97-04-28 -0400, Daniel Berstein wrote:
>I need to delete a file, but don't want to use the system() function,
>cause it has to be "transparent" to the user. So I got this bright
>idea of using DOS interrupts (#21). At the end is the code I used, but
>it doesn't work... I keep getting DOS error 2 (file not found) and
>5 (access denied). Can anyone tell me what is wrong? Is there any
>other way to that?
>I also needed to copy a file but I solve that with a loop of getc() and
>puts() until an EOF.. is there another eficient way?
>
>Thanks.
>
>
>-------------CUT HERE--------------
>
>-- SYS_DEL()
>-- Uses DOS INT #21, service #41 to delete a file given an ASCIIZ filename
>-- Returns 1 if succesfull, else return 0 and displays DOS error code
>
>-- INT reference: HelpPC 2.1
>function sys_del(sequence filename)
> sequence reg_list
> integer buff
>
> buff = allocate_low(length(filename)+1)
> poke(buff,filename)
> poke(buff+length(filename),0)
>
> reg_list = repeat(0,10)
>
> reg_list[REG_AX] = #4100
> reg_list[REG_DS] = floor(buff/16)
> reg_list[REG_DX] = remainder(buff,16)
>
> reg_list = dos_interrupt(#21,reg_list)
> free_low(buff)
>
> if remainder(reg_list[REG_FLAGS],2) != 0 then
> puts(1, "DOS error number :")
> print(1,reg_list[REG_AX])
> puts(1,"\n")
> return 0
> else
> return 1
> end if
>end function
>
>--------END OF CODE--------
I tested it on my computer without any problem.
I attached copy.ex which use dos interrupt #21 to copy a file. You need
doswrap.e
to use it. If you don't have it you can find it on Euphoria Official home
page or
drop me an e-mail I'll send it to you.
--=====================_862467637==_
-- copying file demo.
include doswrap.e
constant BUFF_SIZE = power(2,15)
function CopyFile(sequence Source, sequence Dest)
atom buffer
integer FSrc, FDest, NbRead, junk
FSrc = DosOpen(Source,READ)
if FSrc = -1 then
return 0
end if
FDest = DosCreate(Dest,0)
if FDest = -1 then
return 0
end if
buffer = allocate_low(BUFF_SIZE)
if buffer = 0 then
return 0
end if
NbRead = BlockRead(FSrc,buffer,BUFF_SIZE)
while NbRead > 0 do
if BlockWrite(FDest,buffer,NbRead) = -1 then
junk = DosClose(FSrc)
junk = DosClose(FDest)
free_low(buffer)
return 0
end if
NbRead = BlockRead(FSrc,buffer,BUFF_SIZE)
end while
junk = DosClose(FSrc)
junk = DosClose(FDest)
free_low(buffer)
return 1
end function
--=====================_862467637==_
Jacques Deschenes
Baie-Comeau, Quebec
Canada
desja at quebectel.com
--=====================_862467637==_--
7. Re: Deleting a file
Jacques Deschenes wrote:
> I tested it on my computer without any problem.
Ooops, I made the function OK, but I just realized I was calling it
bad... I used '\' instaed of '\\' for the file path :P Stupid thing!!!
> I attached copy.ex which use dos interrupt #21 to copy a file. You need
> doswrap.e
> to use it. If you don't have it you can find it on Euphoria Official home
> page or
> drop me an e-mail I'll send it to you.
Thanks, I got your files.
--
************************************
This message sent by Daniel Berstein
************************************
email: architek at geocities.com
homepages: http://www.geocities.com/SiliconValley/Heights/9316
http://www.cybercity.hko.net/silicon_valley/architek
