writing 0x0A to a bin file without having it automatically write 0x0D

[MCondon77]

This is probably a common problem, but as a novice programmer I'm
trying to figure out how to write 0x0A to a BIN file without having it
automatically write 0x0D. Here's an example of the code:
tmp_ifp = fopen("tmp_name .bin", "w");
fprintf(tmp_ifp , "%c", 0x0A);

When I open the tmp_name.bin file with a hex editor you notice that
both 0x0D and 0x0A are written. I tried using fwrite, but the same
thing occurs. Any ideas?

Thanks....

[John Devereux]

MC*******@gmail .com writes:

This is probably a common problem, but as a novice programmer I'm
trying to figure out how to write 0x0A to a BIN file without having it
automatically write 0x0D. Here's an example of the code:
tmp_ifp = fopen("tmp_name .bin", "w");
fprintf(tmp_ifp , "%c", 0x0A);

When I open the tmp_name.bin file with a hex editor you notice that
both 0x0D and 0x0A are written. I tried using fwrite, but the same
thing occurs. Any ideas?

You need to open the file in "binary" mode, e.g.

tmp_ifp = fopen("tmp_name .bin", "wb");
--

John Devereux

[Ben Pfaff]

MC*******@gmail .com writes:

This is probably a common problem, but as a novice programmer I'm
trying to figure out how to write 0x0A to a BIN file without having it
automatically write 0x0D. Here's an example of the code:
tmp_ifp = fopen("tmp_name .bin", "w");

Use binary mode: "wb" instead of "w".
--
"When in doubt, treat ``feature'' as a pejorative.
(Think of a hundred-bladed Swiss army knife.)"
--Kernighan and Plauger, _Software Tools_

[Richard G. Riley]

On 2006-03-13, MC*******@gmail .com <MC*******@gmai l.com> wrote:

This is probably a common problem, but as a novice programmer I'm
trying to figure out how to write 0x0A to a BIN file without having it
automatically write 0x0D. Here's an example of the code:
tmp_ifp = fopen("tmp_name .bin", "w");
fprintf(tmp_ifp , "%c", 0x0A);

When I open the tmp_name.bin file with a hex editor you notice that
both 0x0D and 0x0A are written. I tried using fwrite, but the same
thing occurs. Any ideas?

Thanks....

I think these routines can convert 0xa to a system defined
line terminator : which I guess in your case is 0xD,0xA.

Check the options which can follow "w" in your fopen : b or t might
help if memory serves correctly. Since you talk about "bin" file then
"wb" might be your man.

[Jordan Abel]

On 2006-03-13, MC*******@gmail .com <MC*******@gmai l.com> wrote:

This is probably a common problem, but as a novice programmer I'm
trying to figure out how to write 0x0A to a BIN file without having it
automatically write 0x0D. Here's an example of the code:
tmp_ifp = fopen("tmp_name .bin", "w");
"wb".
fprintf(tmp_ifp , "%c", 0x0A);

When I open the tmp_name.bin file with a hex editor you notice that
both 0x0D and 0x0A are written. I tried using fwrite, but the same
thing occurs. Any ideas?

Thanks....

[Jordan Abel]

On 2006-03-13, Richard G. Riley <rg****@gmail.c om> wrote:

On 2006-03-13, MC*******@gmail .com <MC*******@gmai l.com> wrote:

This is probably a common problem, but as a novice programmer I'm
trying to figure out how to write 0x0A to a BIN file without having it
automatically write 0x0D. Here's an example of the code:
tmp_ifp = fopen("tmp_name .bin", "w");
fprintf(tmp_ifp , "%c", 0x0A);

When I open the tmp_name.bin file with a hex editor you notice that
both 0x0D and 0x0A are written. I tried using fwrite, but the same
thing occurs. Any ideas?

Thanks....

I think these routines can convert 0xa to a system defined
line terminator : which I guess in your case is 0xD,0xA.

Check the options which can follow "w" in your fopen : b or t might
help if memory serves correctly. Since you talk about "bin" file then
"wb" might be your man.

t is not standard C<OT>, and where it is used, it means text mode</OT>.

[Barry Schwarz]

On 13 Mar 2006 14:03:44 -0800, MC*******@gmail .com wrote:

This is probably a common problem, but as a novice programmer I'm
trying to figure out how to write 0x0A to a BIN file without having it
automaticall y write 0x0D. Here's an example of the code:
tmp_ifp = fopen("tmp_name .bin", "w");
fprintf(tmp_if p, "%c", 0x0A);

When I open the tmp_name.bin file with a hex editor you notice that
both 0x0D and 0x0A are written. I tried using fwrite, but the same
thing occurs. Any ideas?

You opened the file in text mode. Therefore, it is not a binary file,
regardless of what the three character extension is. If you want to
process the file in binary mode, open it binary mode.

For additional insurance, don't use fprintf. Use fwrite.
Remove del for email

[Richard Tobin]

In article <bd************ *************** *****@4ax.com>,
Barry Schwarz <sc******@doezl .net> wrote:

For additional insurance, don't use fprintf. Use fwrite.

Huh? How can these be different?

-- Richard

[MikeC_EE99]

Thanks....I opened it with "wb" and it worked. I'm surprised that just
using "w" wouldn't. Why would you want to act on the data being
written to a file in that manner? Doesn't make sense. If someone
wanted a new line then they would just put "\n".
Thanks everyone else for your help too!

[Chris Dollin]

MikeC_EE99 wrote:

Thanks....I opened it with "wb" and it worked. I'm surprised that just
using "w" wouldn't. Why would you want to act on the data being
written to a file in that manner?
So that you write the correct data.
Doesn't make sense.
Does.
If someone wanted a new line then they would just put "\n".

But in a /file/, on some OSs incl Windows, a new line is represented
as \r\n, not just \n. So, for /text streams/, the C library converts
\r\n on input to \n, and \n on output to \r.

If you don't want that to happen, you're not writing a text stream,
so you have to tell C that you want a "binary" file.

--
Chris "sparqling" Dollin
"Who do you serve, and who do you trust?"