OpenEuphoria

Re: Deleting a file

• Posted by Jacques Deschenes <desja at QUEBECTEL.COM> Apr 30, 1997
• 784 views

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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.


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-- 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


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Jacques Deschenes
Baie-Comeau, Quebec
Canada
desja at quebectel.com

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