Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!border3.nntp.dca.giganews.com!Xl.tags.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!nntp.earthlink.com!news.earthlink.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 23 Jul 2012 23:07:50 -0500 Message-ID: <500E1F96.93A@mindspring.com> Date: Tue, 24 Jul 2012 00:07:50 -0400 From: pete Reply-To: pfiland@mindspring.com Organization: PF X-Mailer: Mozilla 3.04Gold (WinNT; I) MIME-Version: 1.0 Newsgroups: comp.lang.c Subject: Re: qsort man page References: <89644623-7e1c-4f8b-9f4d-6443526f0f73@u2g2000yqj.googlegroups.com> <500E17B1.2144@mindspring.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 22 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 4.156.228.78 X-Trace: sv3-TLKDJH7xMOcMCohK4oRU+fn4J6pE3n4ZKP4HDTdD844ipuDk2gaPJaCb79/dwlEDIfXpO/byJoS0sqC!edlLCdaioio86PsxhfMDHELS8SBgNjdpMb1zI/HJ58mssyhkphMPWzJLoLWrAUbC38wxrNS4uvkm!UDtcxamb X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 X-Original-Bytes: 1792 Xref: csiph.com comp.lang.c:23648 pete wrote: > > Bill Cunningham wrote: > > > > This is from the qsort man page. I don't quite understand why there is > > a comment here saying that arguments to this generic function to pass > > to qsort is a pointer to pointer. > > It looks to me like cmpstringp takes > > a generic pointer. Not pointer to pointer. Why does the comment say > > pointer to pointer? > > Because the argument that qsort will pass to cmpstringp, > when qsort calls cmpstringp, > is a pointer to a pointer. The actual pointers passed by qsort could be of any type, but the elements of the array being sorted are pointers, and the pointers passed to cmpstringp from qsort, will point to those pointer elements. -- pete