1. converting carriage return
Hello to group!
I am trying to encrypt a file, using a simple xor routine on each
byte in it.
I find that carriage return-line feed is not converted correctly using getc(),
and can't figure out a fast way to do this.
-- my code
procedure input()
integer file_in
integer file_out
char char_in
char char_out
file_in = open("x.in", "r") --file must exist
file_out = open("x.out","w") --output file
--loop through x.in
while 1 do
char_in = getc(file_in)
if char_in = -1 then
exit
--get out of the loop at end of file
end if
char_out = xor_bits(char_out, #10)
-- write to file
puts(file_out,char_out)
end while
close(file_in)
close(file_out)
puts(1,"DONE!")
end procedure
--
If I do a simple gets, puts the two files are the same,
but if I try to convert each 'char', then the
carriage return/line feed combination is not separated
into two bytes, and is not written correctly (the x0D part
(carriage return)) is lost.
If you can help please email me at dae at paclink.com.
Thanks.
2. Re: converting carriage return
On Sun, 15 Jun 1997 17:39:21 -0700 D & B Edmunds <dae at PACLINK.COM>
writes:
>
>Hello to group!
>
>I am trying to encrypt a file, using a simple xor routine on each
>byte in it.
>I find that carriage return-line feed is not converted correctly using
>getc(),
>and can't figure out a fast way to do this.
>--snip
> file_in = open("x.in", "r") --file must exist
> file_out = open("x.out","w") --output file
USE:
file_in = open("x.in", "rb")
file_out = open("x.out","wb")
Open the files in binary mode.
3. Re: converting carriage return
- Posted by Daniel Berstein <architek at GEOCITIES.COM>
Jun 15, 1997
-
Last edited Jun 16, 1997
D & B Edmunds wrote:
> procedure input()
> integer file_in
> integer file_out
> char char_in
> char char_out
> file_in = open("x.in", "r") --file must exist
^^^^
WRONG!
> file_out = open("x.out","w") --output file
... etc....
Your problem is that you opened the file as "text read" by means
of the open("x.in","r"), Euphoria automatically converts \n chars. You
should use the "rb" option that opens the file as "binary", so no
conversion is made and you'll get the two byte pair you expect. Notice
that you should also open the output file as binary ("wb") so there is
no chance that Euphoria makes any change.
Hope this helps you ;)
--
Regards,
Daniel Berstein
architek at geocities.com
http://www.geocities.com/SiliconValley/Heights/9316
