Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.c > #103657
| From | Joe Pfeiffer <pfeiffer@cs.nmsu.edu> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: better atoi |
| Date | 2017-02-10 21:59 -0700 |
| Organization | A noiseless patient Spider |
| Message-ID | <1bwpcxiaq2.fsf@pfeifferfamily.net> (permalink) |
| References | <853138f9-54d1-435f-90d5-ef75a38e65bf@googlegroups.com> <1b1sv5k98w.fsf@pfeifferfamily.net> <874m011wzn.fsf@bsb.me.uk> |
Ben Bacarisse <ben.usenet@bsb.me.uk> writes: > Joe Pfeiffer <pfeiffer@cs.nmsu.edu> writes: > >> fir <profesor.fir@gmail.com> writes: >>> >>> http://www.cplusplus.com/reference/cstdlib/strtol/ >>> >>> it is said that strtol sets errno to ERANGE but is >>> not mentioned with wrong value, so im not sure if >>> it can be uniformly checked (probably yest though >>> but only not noted (i not checked it though)) >> >> It says it returns LONG_MAX or LONG_MIN in this case (so it appears it >> is possible that if the string does in fact represent one of those >> values, you can't reliably detect the conversion was successful -- as >> we've seen in other places, we can't rely on ERRNO being 0 on success. >> We'd sort of hope for it in this function...). > > I don't think that's the right reading of the situation. Here's the > relevant text (with stuff about threads elided): > > "The value of errno [...] is zero at program startup [...], but is > never set to zero by any library function. The value of errno may be > set to nonzero by a library function call whether or not there is an > error, provided the use of errno is not documented in the description > of the function in this International Standard." I hope you're right -- as I remember it, the documentation required is a statement saying it *doesn't* set it unless there is an error. My recollection is that some functions (I want to say open()?) will set it, even though there is no error. You have to check the return value for error, and then look at errno to see what the error is.
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
better atoi fir <profesor.fir@gmail.com> - 2017-02-10 12:24 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-10 12:35 -0800
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-10 14:48 -0700
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-10 14:12 -0800
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-10 22:36 -0700
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-11 01:07 -0800
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-11 10:10 -0700
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-11 09:26 -0800
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-11 15:36 -0700
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 00:18 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 00:31 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 03:47 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 04:22 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 06:08 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 06:13 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 07:31 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 08:02 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 08:08 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 08:17 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 08:23 -0800
Re: better atoi Robert Latest <boblatest@yahoo.com> - 2017-02-19 11:11 +0000
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-11 17:33 +0000
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-11 15:35 -0700
Re: better atoi "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-11 17:52 -0500
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-11 18:53 -0700
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-10 22:50 +0000
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-10 21:59 -0700
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-11 12:08 +0000
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-11 09:39 -0700
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-11 17:26 +0000
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-11 15:30 -0700
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-11 22:58 +0000
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-11 18:48 -0700
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-12 02:16 +0000
Re: better atoi "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-12 09:57 -0500
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 07:27 -0800
Re: better atoi jameskuyper@verizon.net - 2017-02-12 08:44 -0800
Re: better atoi fir <profesor.fir@gmail.com> - 2017-02-12 09:15 -0800
Re: better atoi Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-02-12 09:44 -0800
Re: better atoi BartC <bc@freeuk.com> - 2017-02-12 18:32 +0000
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-12 18:56 +0000
Re: better atoi BartC <bc@freeuk.com> - 2017-02-12 19:18 +0000
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-13 00:16 +0000
Re: better atoi BartC <bc@freeuk.com> - 2017-02-13 01:56 +0000
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-13 10:44 +0000
Re: better atoi BartC <bc@freeuk.com> - 2017-02-13 11:38 +0000
Re: better atoi Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-13 14:37 +0000
Re: better atoi BartC <bc@freeuk.com> - 2017-02-13 15:00 +0000
Re: better atoi Keith Thompson <kst-u@mib.org> - 2017-02-12 11:15 -0800
Re: better atoi BartC <bc@freeuk.com> - 2017-02-12 19:25 +0000
Re: better atoi Keith Thompson <kst-u@mib.org> - 2017-02-12 11:54 -0800
Re: better atoi supercat@casperkitty.com - 2017-02-12 13:13 -0800
Re: better atoi Keith Thompson <kst-u@mib.org> - 2017-02-10 15:16 -0800
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-10 22:01 -0700
Re: better atoi Keith Thompson <kst-u@mib.org> - 2017-02-11 01:30 -0800
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-10 22:26 -0700
Re: better atoi Nick Bowler <nbowler@draconx.ca> - 2017-02-11 00:26 +0000
Re: better atoi Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-10 22:32 -0700
Re: better atoi "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-19 11:10 -0500
csiph-web