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| From | "Chris M. Thomasson" <nospam@nospam.nospam> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Floating point to string, and back via `%a'... |
| Date | 2015-07-22 12:46 -0700 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <moorva$su7$1@speranza.aioe.org> (permalink) |
How in the heck can I use the `%a' format specifier in
conjunction with sprintf/sscanf so that I can convert a
floating point to a string, and back? I have some code,
but it does not work with `%a'. Damn!
Also, why does it seem to work for a %f %lf sprintf to sscanf pair?
_______________________________________________________________
#include <stdio.h>
int
main(void)
{
char buf[256] = { '\0' };
double no = 1.0123456789;
printf("no = %.10f\n\n", no);
/* try to use default precision `%a' with sprintf/sscanf */
{
sprintf(buf, "%a", no);
double nc = 0.0;
int status = sscanf(buf, "%a", &nc);
if (! status || status == EOF)
{
printf("sscanf `%%a' error!\n");
}
printf("(%%s):buf = %s\n", buf);
printf("(%%a):nc = %f\n\n", nc);
}
/* try to use custom precision `%.10a' with sprintf/sscanf */
{
sprintf(buf, "%.10a", no);
double nc = 0.0;
int status = sscanf(buf, "%.10a", &nc);
if (! status || status == EOF)
{
printf("sscanf `%%.10a' error!\n");
}
printf("(%%s):buf = %s\n", buf);
printf("(%%.10a):nc = %.10f\n\n", nc);
}
/* try to use default precision `%f' with sprintf/sscanf */
{
sprintf(buf, "%f", no);
double nc = 0.0;
int status = sscanf(buf, "%lf", &nc);
if (! status || status == EOF)
{
printf("sscanf %%lf error!\n");
}
printf("(%%s):buf = %s\n", buf);
printf("(%%f):nc = %f\n\n", nc);
}
/* try to use custom precision `%.10f' with sprintf/sscanf */
{
sprintf(buf, "%.10f", no);
double nc = 0.0;
int status = sscanf(buf, "%lf", &nc);
if (! status || status == EOF)
{
printf("sscanf %%lf error!\n");
}
printf("(%%s):buf = %s\n", buf);
printf("(%%.10f):nc = %.10f\n\n", nc);
}
return 0;
}
_______________________________________________________________
What am I doing wrong? How do I use `%a' properly!
;^O
Back to comp.lang.c | Previous | Next — Next in thread | Find similar | Unroll thread
Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 12:46 -0700
Re: Floating point to string, and back via `%a'... James Kuyper <jameskuyper@verizon.net> - 2015-07-22 16:19 -0400
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 13:49 -0700
Re: Floating point to string, and back via `%a'... Keith Thompson <kst-u@mib.org> - 2015-07-22 14:01 -0700
Re: Floating point to string, and back via `%a'... James Kuyper <jameskuyper@verizon.net> - 2015-07-22 17:18 -0400
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 14:22 -0700
Re: Floating point to string, and back via `%a'... Keith Thompson <kst-u@mib.org> - 2015-07-22 13:40 -0700
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 14:01 -0700
Re: Floating point to string, and back via `%a'... Keith Thompson <kst-u@mib.org> - 2015-07-22 14:12 -0700
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 14:20 -0700
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 14:24 -0700
Re: Floating point to string, and back via `%a'... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-22 21:30 +0000
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 14:39 -0700
Re: Floating point to string, and back via `%a'... Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2015-07-22 19:49 -0600
Re: Floating point to string, and back via `%a'... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-22 22:28 +0100
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 14:34 -0700
Re: Floating point to string, and back via `%a'... Keith Thompson <kst-u@mib.org> - 2015-07-22 14:58 -0700
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 15:43 -0700
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 15:45 -0700
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 15:51 -0700
Re: Floating point to string, and back via `%a'... Robert Wessel <robertwessel2@yahoo.com> - 2015-07-22 18:21 -0500
Re: Floating point to string, and back via `%a'... Keith Thompson <kst-u@mib.org> - 2015-07-22 16:58 -0700
Re: Floating point to string, and back via `%a'... Keith Thompson <kst-u@mib.org> - 2015-07-22 16:52 -0700
Re: Floating point to string, and back via `%a'... Keith Thompson <kst-u@mib.org> - 2015-07-22 17:08 -0700
Re: Floating point to string, and back via `%a'... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-23 00:01 +0100
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-22 19:40 -0700
Re: Floating point to string, and back via `%a'... Keith Thompson <kst-u@mib.org> - 2015-07-22 22:32 -0700
Re: Floating point to string, and back via `%a'... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-23 11:07 +0100
Re: Floating point to string, and back via `%a'... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-23 11:25 +0100
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-24 11:44 -0700
Re: Floating point to string, and back via `%a'... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-24 11:47 -0700
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