Hi. On Mon, Aug 27, 2018 at 04:49:06PM +0200, to...@tuxteam.de wrote: > On Mon, Aug 27, 2018 at 04:32:26PM +0300, Reco wrote: > > Hi. > > > > On Mon, Aug 27, 2018 at 09:08:19AM -0400, Greg Wooledge wrote: > > > > Hm. Interfaces man page refers to wordexp(3), but this one doesn't say > > > > anything about sorted results > > > > > > In the absence of such information, the best thing to conclude is that > > > the order is unspecified. It may be using the raw unsorted directory > > > contents from readdir(3), or it may be starting them all in parallel > > > threads, in which case the order will be nondeterministic. > > > > wordexp(3) invokes glob(3). > > > > glob(3) states that one *needs* to specify GLOB_NOSORT to get resultes > > pathnames in no particular order, as by default the result will be > > sorted. > > > > Unless I'm reading glibc source wrong, the only non-default argument > > that wordexp(3) passes to glob(3) is GLOB_NOCHECK. > > Thanks for looking into the source. > > The remaining problem is, since the doc seems pretty fuzzy about that, > whether one can rely on this behaviour, or whether this is just an > implementation detail which can change under one at any time.
Assuming that glibc stays true to POSIX, 2001 standard - [1] says that: The wordexp() function shall store the number of generated words into pwordexp->we_wordc and a pointer to a list of pointers to words in pwordexp->we_wordv. Each individual field created during field splitting (see the Shell and Utilities volume of IEEE Std 1003.1-2001, Section 2.6.5, Field Splitting) or pathname expansion (see the Shell and Utilities volume of IEEE Std 1003.1-2001, Section 2.6.6, Pathname Expansion) shall be a separate word in the pwordexp->we_wordv list. The words shall be in order as described in the Shell and Utilities volume of IEEE Std 1003.1-2001, Section 2.6, Word Expansions. Last sentence says to me that wordexp output should be always sorted. Latest edition I could find - 2017 standard - [2] contains similar wording. Reco [1] http://pubs.opengroup.org/onlinepubs/009695299/functions/wordexp.html [2] http://pubs.opengroup.org/onlinepubs/9699919799/
