OpenEuphoria

2. Re: delete bytes?

• Posted by Evan Marshall <1evan at sbcglobal.net> Mar 19, 2006
• 557 views

Salix wrote:
> 
> I have a text file open and I want to write a few words after the 25th byte
> and delete the rest. What should I do?
> 
> }}}
<eucode>

> -- ... and now what?
> </eucode>
{{{

> 
> Regards,
> 
> Salix



 include file.e
 
 integer fn, fx
 fn = open("mytext.txt", "u")
 fx = seek(fn, 25) 
 puts(fn,"Aha!\n") 
 puts(fn,0)

4. Re: delete bytes?

• Posted by Bernie Ryan <xotron at bluefrog.com> Mar 19, 2006
• 588 views
• Last edited Mar 20, 2006

Salix wrote:
> 
> Evan Marshall wrote:
> > 
> > Salix wrote:
> > > 
> > > I have a text file open and I want to write a few words after the 25th
> > > byte
> > > and delete the rest. What should I do?
> > >  
> > 
> >  include file.e
> >  
> >  integer fn, fx
> >  fn = open("mytext.txt", "u")
> >  fx = seek(fn, 25) 
> >  puts(fn,"Aha!\n") 
> >  puts(fn,0)
> 
> The puts(fn,0) doesn't seem to delete everything if there are \n characters
> in the text. 
> 
> Regards,
> 
Salix:

  Try This:

include file.e

integer fn, fx fn = open("mytext.txt", "u") fx = seek(fn, 25) puts(fn,"Aha!\n") print(fn,26) ctl-Z or 26 #1A close(fn) }}}

Bernie

My files in archive: WMOTOR, XMOTOR, W32ENGIN, MIXEDLIB, EU_ENGIN, WIN32ERU, WIN32API

Can be downloaded here: http://www.rapideuphoria.com/cgi-bin/asearch.exu?dos=on&win=on&lnx=on&gen=on&keywords=bernie+ryan }}}

6. Re: delete bytes?

• Posted by Evan Marshall <1evan at sbcglobal.net> Mar 19, 2006
• 554 views
• Last edited Mar 20, 2006

Oops,

include file.e
 
 integer fn, fx
 fn = open("mytext.txt", "u")
 fx = seek(fn, 25) 
 puts(fn,"Aha!\n")
 print(fn,26) -- ctl-Z or 26 #1A
 close(fn)

actually makes

abcdefghijklmnopqrstuvwxyz12346789 become

abcdefghijklmnopqrstuvwxyAha!
26798

which seems really strange.

8. Re: delete bytes?

• Posted by "Greg Haberek" <ghaberek at gmail.com> Mar 20, 2006
• 563 views

> I have a text file open and I want to write a few words after the 25th by=
te and delete the rest. What should I do?

its only 25 bytes, why not do this?

include get.e
include file.e

integer fn
sequence bytes

-- open file for reading
fn = open("mytext.txt", "r")
-- buffer the data
bytes = get_bytes(fn, 25)
-- close file
close(fn)

-- open file for writing
fn = open("mytext.txt", "w")
-- output buffer
puts(fn, bytes)
-- output our data
puts(fn,"Aha!\n")
-- close the file
close(fn)

~Greg

10. Re: delete bytes?

• Posted by Salix <salix at freemail.hu> Mar 20, 2006
• 555 views

Greg Haberek wrote:
> 
> > I have a text file open and I want to write a few words after the 25th by=
> te and delete the rest. What should I do?
> 
> its only 25 bytes, why not do this?
> 
> ... 

Because in reality it is not 25 bytes but can be anything (including 837 252
938)
depending on the situation. I just tried to "strip down" the problem. 

My first thought was to finish the writting with puts(fn,EOF) but obviously
didn't
worked. :-] Following Hayden's and Jürgen's suggestions I try to find some
examples
in other languages on the web. (But frankly, I do not expect too much from this 
knowing my programming knowledge...)

More tips and advices are welcome!

Regards,

Salix

12. Re: delete bytes?

• Posted by Brian Broker <brian_broker at yahoo.com> Mar 20, 2006
• 568 views

Hayden McKay wrote:
> 
> 
> You could use interrupt 13h to sector read the disk's FAT(s), look for the
> file entry and modify the file's size before sector writting back to disk.
> 
> Search www for 'Creating A Bootdisk' or 'Modifying the VFAT', I've seen a
> few good examples out there in the past.
> 
> Regards,
>     Hayden
> 
> Q. How many programmers doe's it take to change a lightbulb?
> A. None, its a hardware problem!

I don't know about you but I rarely "get it right" the first time I write a
program or routine.  This would be a rather risky approach.

The only safe thing I can think of is to re-write the file and let the OS take
care of it.  Isn't that why we have operating systems?

-- Brian