On Sun, May 26, 2024 at 06:38:35PM +0200, Alejandro Colomar wrote: > Hi Emanuele, > > On Sun, May 26, 2024 at 05:11:58PM GMT, Emanuele Torre wrote: > > > On Sun, May 26, 2024 at 04:19:30PM GMT, Emanuele Torre wrote: > > > > I've just noticed that ptsname.3 is also missing #define _XOPEN_SOURCE > > > > in its synopsis; however #define _XOPEN_SOURCE does not seem to work. > > > Did you define it to 500, or an empty value? > > > > empty value. > > Hmm. > > > > You need to define it to an appropriate value. (The synopsis is a bit > > > misleading, and we could/should specify the minimum value.) > > > > I did notice the > > > > ptsname(): > > Since glibc 2.24: > > _XOPEN_SOURCE >= 500 > > glibc 2.23 and earlier: > > _XOPEN_SOURCE > > > > But that is the same text that appears in grantpt.3 and unlockpt.3, and > > they get included with just _XOPEN_SOURCE. > > > > I also noticed it this morning when I sent my patch for grantpt.3, but I > > ignored it assuming I probably misunderstood its meaning since it worked > > with just _XOPEN_SOURCE. > > I also noticed and ignored it, since I saw the same text in the other > pages. Yes, I copied the line from unlockpt.3 after seeing it there, and seeing it resolved the issue. > > > Does this mean that my grantpt.3 patch is wrong? > > > > And that #define _XOPEN_SOURCE in the synopsys of unlockpt.3 is also > > wrong? > > Regardless of it being correct or not, I think using the definition > used by newer glibc versions is better, so we could update the SYNOPSIS > of all pages to show the requirements of the latest glibc. > > > I should not use just #define _XOPEN_SOURCE without a value in my > > programs if I want to use ptsname(3), grantpt(3), unlockpt(3)? > > TBH, I don't know. AFAICS, _XOPEN_SOURCE without specifying a value > means POSIX.1‐1990 (maybe? not sure). That is so obsolete these days > that I don't know what it means. Does it provide ptsname(3)? I don't > know. But yeah, I'd say just don't use it. > > These days, POSIX.1-2001 is granted everywhere (except maybe some dying > proprietary systems), and even POSIX.1-2008 if you restrict yourself to > Linux and the BSDs. I suggest using the flags that enable one of these > more recent standards. Yes, I guess when necessary it's probably easier to just always use #define _GNU_SOURCE instead of messing with _XOPEN_SOURCE, _POSIX_C_SOURCE, etc. o/ emanuele6
