float to string conversion problem

[LEJARRE Patrick]

The following source eliminates all sigificant decimals. Can someone help me to fix this issue ?

#include
int main()
{
float num = 10.55164516854;
char s[80];
sprintf(s, "%10.10f", num); /* write the double to a string */
printf("Here is the result: %s\n", s);
return 0;
}
Result: Here is the result: 10.0000000000
but should be 10.5516451685

Many thanks in advance.

[benoit Bruckert]

Hello Patrick,
What is the compiler ?
I treid this program and it worked fine with cc (the K&R from HP , not the Ansi) and with gcc.
Any options with cc ? What version of HPUX ? of cc/gcc ?

hope that help
Benoit

[T G Manikandan]

It is working for me using gcc.
Might be your compiler is not supporting this option of string to float conversion.


Thanks

[LEJARRE Patrick]

hi Benoit,

HP-UX 11.00 - C/ANSIC - cc with no option, but you can easily add some.

Bye

[benoit Bruckert]

I don't have the Ansi C compiler on my site !! Then I can't test with this compiler...
I made the test on a linux, it's OK also. That's very strange.
You can try with gcc (install it on your HP-UX, it's available on many portal center), don't forget binutils.

You can also try with a double instead of a float...

[A. Clay Stephenson]

I could only reproduce your problem (more or less) with ANSI/C with these options:
cc -Ac +r myfile.c

The result I got was 0.00000000000. It appears that you must be using the +r which inhibits the automatic promotion of float to double when passing arguments (in this case to sprintf). In this context, it makes sense what is happening.

Note: +r may be being set in CCOPTS.

To test if this is the problem, make this change:
sprintf(s,"%10.10f",(double) num);