Re: lib/59198: Reject negative input in strtou(3), reporting ERANGE

["Alejandro Colomar via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR lib/59198; it has been noted by GNATS.

From: Alejandro Colomar <alx%kernel.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: Bruno Haible <bruno%clisp.org@localhost>
Subject: Re: lib/59198: Reject negative input in strtou(3), reporting ERANGE
Date: Fri, 21 Mar 2025 21:34:42 +0100

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 From: Alejandro Colomar <alx%kernel.org@localhost>
 To: gnats-bugs%netbsd.org@localhost
 Cc: Bruno Haible <bruno%clisp.org@localhost>
 Subject: Re: lib/59198: Reject negative input in strtou(3), reporting ERANGE
 References: <pr-misc-59198%gnats.netbsd.org@localhost>
  <20250319232212.8609C1A923C%mollari.NetBSD.org@localhost>
  <20250319232500.4D8401A923C%mollari.NetBSD.org@localhost>
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 In-Reply-To: <knzempljqvci4o5v4qnunnog7l5yarhc5ttxktgyynkrfzyniv@2yj6ku46u76m>
 
 On Fri, Mar 21, 2025 at 09:25:38PM +0100, Alejandro Colomar wrote:
 > Hi,
 >=20
 > Actually, considering the name strtou(3), which is about **unsigned**
 > integers, maybe negative numbers should not trigger an ERANGE error, but
 > actually an ECANCELED error.  The sign, even a positive sign, should not
 > be part of an unsigned number.
 >=20
 > Here are some example implementations for this:
 >=20
 > 	unsigned long
 > 	strtoul_nn(const char *restrict s, char **restrict endp, int base)
 > 	{
 > 		while (isspace((unsigned char) *s))
 > 			s++;
 > 		if (!isdigit((unsigned char) *s))
 
 This should call isxdigit(3).
 
 > 			return 0;
 >=20
 > 		return strtoul(s, endp, base);
 > 	}
 >=20
 > 	uintmax_t
 > 	strtou_nn(const char *restrict s, char **restrict endp, int base,
 > 	    uintmax_t min, uintmax_t max, int *status)
 > 	{
 > 		while (isspace((unsigned char) *s))
 > 			s++;
 > 		if (!isdigit((unsigned char) *s)) {
 
 This should call isxdigit(3).
 
 > 			if (status)
 > 				*status =3D ECANCELED;
 > 			return min;
 > 		}
 >=20
 > 		return strtou(s, endp, base, min, max, status);
 > 	}
 >=20
 > I'm going to expand the BUGS section in the strtoul(3) Linux manual
 > page, and mention the strtoul_nn() example as a workaround for this bug
 > in the standard strtoul(3).
 >=20
 > The strtou_nn() should be the ideal behavior of strtou(3).
 >=20
 > (I hope this arrives at the bug ticket.)
 >=20
 >=20
 > Cheers,
 > Alex
 >=20
 > --=20
 > <https://www.alejandro-colomar.es/>
 
 
 
 --=20
 <https://www.alejandro-colomar.es/>
 
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