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Re: printf() woes

Rick Mann wrote:

On Jan 30, 2008, at 11:10 AM, Jeff Johnston wrote:

Rick Mann wrote:
Hi. I'm using newlib 1.14 on an Atmel ARM processor, and printf() is behaving strangely.
The following code
printf("1. Hello worldCRLF1\r\n");
printf("2. Hello worldCRLF\r\n");
printf("3. Hello worldCRLF\r\nHello worldCRLF\r\n");
printf("4. Hello worldLF\nHello worldLF\n");
printf("5. Hello worldNULL");
printf("6. Hello worldLF\n");
3. Hello worldCRLF1
4. Hello worldLF
Hello worldLF6. Hello worldLF
Using snprintf() works just fine.

Did you attempt to write the result out?

I'm not sure I understand what you mean. I put, in the original post, the output of those lines of code. It fails to print many of them.

What I meant is did you output the snprintf() output to the terminal
(e.g. via write syscall) to see what that output produces on the terminal. It may not be newlib's problem.

Newlib's printf() is doing something with newlines, and printf() calls without newline, and not handling it the way I really want. Perhaps it's a configuration things somewhere, but I don't really know where to look.
Any suggestions?

I would suggest upgrading to newlib 1.16.0 to see if any fixes were made that solve your problem. Looking through the ChangeLog, none are obvious, but it still helps to be current so others can better help you.

Is there a way to upgrade newlib without rebuilding all of gcc?

Yes. You can build newlib in a separate build directory. Just make sure you have installed all the cross-tools (including gcc) somewhere and put the install dir on your path.

Next, I would suggest debugging inside _sfvwrite() to see what it thinks it is doing. I would also suggest putting breakpoints inside the _write syscall to see what it is being called with each time. This should help you pinpoint the problem.

Sadly, I have no debugging capabilities right now (other than printf--ha!).

Ok, use the write syscall to fd 2.

-- Jeff J.

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