On 09/11/2023 00:29, Alejandro Colomar wrote: > Hi Pail, > > On Wed, Nov 08, 2023 at 03:31:38PM -0800, Paul Eggert wrote: >> On 11/8/23 14:11, Alejandro Colomar wrote: >>> I just don't think we need, >>> as GNU or Linux projects, to be restricted to the decisions of ISO. We >>> can realize that certain functions are bad, and mark them as deprecated >>> in our scope. >> >> There's enough use of strncpy for the intended use (smallish fixed size >> character arrays that are null padded, not null terminated) that saying it's >> deprecated would likely cause more trouble than it's worth. It's not just >> utmp and tar; it's also socket programming (sun_path) and I'm sure other >> stuff. >> >> Were we designing the C library from scratch I'd agree with you: in that >> context, strncpy would clearly be more trouble than it's worth. But now that >> we're stuck with strncpy we have better things to do than try to deprecate >> it. > > No, no, I'm not trying to deprecate it. I was just saying that *iff* > all of its uses were dead, I'd deprecate it. But they're clearly not > dead, so it's a perfect function for those cases. > >> >> Instead of saying "deprecate" I suggest we say something like "This function >> is generally a poor choice for processing strings" and point to the longer >> man page about strings in general. That's what the glibc manual does and it >> works reasonably well. > > Yes, I've done something like this. string_copying(7) recommends > avoiding fixed-width null-padded buffers in APIs. But for those use > cases that already exist, this is the function to use. https://man7.org/linux/man-pages/man7/string_copying.7.html Rather than "catenation", in my experience "concatenation" is the common term to explain what it does. There are quite a few on that page. Probably other man pages too. How about following the style of the other man pages that put the notes about each function below them? (rather than above) https://man7.org/linux/man-pages/man3/string.3.html size_t strlen(const char *s); Return the length of the string s. At the moment on string_copying there are // comments on the line above each function. So the presentation of the information is different: // Copy/catenate a string. char *strcpy(char *restrict dst, const char *restrict src); char *strcat(char *restrict dst, const char *restrict src); Kind regards Jonny
