Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
| From | James Kuyper <jameskuyper@verizon.net> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Floating point to string, and back via `%a'... |
| Date | 2015-07-22 16:19 -0400 |
| Organization | Self |
| Message-ID | <55AFFAEC.9060104@verizon.net> (permalink) |
| References | <moorva$su7$1@speranza.aioe.org> |
On 07/22/2015 03:46 PM, Chris M. Thomasson wrote: > 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! It would help if you identified how it failed to work. Which compiler are you using? What options did you select when compiling? Did compilation fail with error messages? If so, provide those messages. Did it not do what you expected it to do when you ran it? If so, tell us what it actually did. > Also, why does it seem to work for a %f %lf sprintf to sscanf pair? Because of the 'l'. ... > double nc = 0.0; > int status = sscanf(buf, "%a", &nc); "%a" is for float. Use "%la" for double (7.21.6.2p11). Similarly, you should be using "%lf", not "%f". This applies to all of your sscanf() calls. The 'l' is unnecessary for printf() and sprintf(), because floats are automatically promoted to double when the type of the corresponding argument of a function has not been declared in a function prototype. However, it is also permitted, to allow the same format string to be used for both sprintf() and sscanf(). ... > int status = sscanf(buf, "%.10a", &nc); sscanf() does not allow you to specify the precision, and '.' is not a permitted character in sscanf() directives.
Back to comp.lang.c | Previous | Next — Previous in thread | 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
csiph-web