Date: Fri, 15 Apr 2005 07:08:40 +1000 From: Peter Jeremy <PeterJeremy@optushome.com.au> To: Ted Unangst <tedu@zeitbombe.org> Cc: freebsd-current@freebsd.org Subject: Re: strtonum(3) in FreeBSD? Message-ID: <20050414210840.GT89047@cirb503493.alcatel.com.au> In-Reply-To: <Pine.BSO.4.61.0504132206030.18943@af.pbqrshfvbavf.pbz> References: <Pine.BSO.4.61.0504132206030.18943@af.pbqrshfvbavf.pbz>
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On Wed, 2005-Apr-13 22:23:42 -0400, Ted Unangst wrote: >> Based on the man page, I see the following deficiencies: >> 1) No support for bases other than 10 > >it's meant for converting numbers, not addresses. if you want strtoaddr, >or strtomode_t, there's still strtol. the idea was to keep it simple. >most people think about sending 10 packets, not 0xa packets. The manpage states: "The strtonum function was designed to facilitate safe, robust programming and overcome the shortcomings of the atoi(3) and strtol(3) family of interfaces." This implies (to me anyway) that it is a replacement for strtol(), though it only implements a subset of strtol() functionality. >> 2) No provision to return the end of the converted string > >exactly, there's no need for it. strtonum is used to convert a "string >containing a number" not a "string containing a number optionally followed >by some other things which are not the number". if strlen() won't give >you want you want, it means the input is not appropriate for strtonum. This means you can't use it in a simple parser to handle the user entering "10k" to mean 10000 or "128m" to mean 128000000. dd(1) needs this and I've used it on occasion. Again, it's being sold as a replacement for strtol() but isn't. >> 3) No simple way to distinguish errors from a valid zero. > >check errstr. i updated the man page to clearly reflect the fact it will >be NULL on sucess, that was the original intention. I suspected so but that needs to be clearly documented. >do, what it wouldn't do, and how one would use it. you don't have to >agree with our decisions, but it sounds like you're descending in on >"strtol but not called strtol". I think strtonum() is a good atoi() family replacement. It's not a general replacement for strtol() but the man page doesn't distinguish between atoi() and strtol(). If the manpage stated that it was an atoi() replacement and only referenced strtol() as a side-note then my first two objections would vanish. Note that there are cases in the tree (I've found one in apmd(8)) where atoi() is passed a string that is known to have trailing non-numeric characters that should be ignored. Removing the trailing characters would make the lexer more complex. -- Peter Jeremy
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