NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part1/7688

Internet Message Format | 1996-08-05 | 1.6 KB

Path: keats.ugrad.cs.ubc.ca!not-for-mail
From: [e-mail] (Kazimir Kylheku)
Newsgroups: comp.lang.c
Subject: Re: more problems with qsort
Date: 26 Feb 1996 13:43:35 -0800
Organization: Computer Science, University of B.C., Vancouver, B.C., Canada
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: keats.ugrad.cs.ubc.ca

In article <[e-mail]>,
James D. Watson <[e-mail]> wrote:
 >Hi folks --
 >
 >after reading the FAQ entries about qsort, I thought I had my problem
 >licked, but it seems not.
 >
 >Architecture: SunOS 4.1.3 with ANSI-C compiler.
 >
 >I'm doing some file manipulation and between steps A and B, I need to sort.
 >For various reasons, I don't want to popen() to the sort utility--I want to
 >use qsort.  Here's what I'm doing:
 >
 >   get number of lines in the file
 >   (char**)malloc with enough room for all lines
 >   for each line in the file {
 >     (char*)malloc(90)  /* 90 is enough room for each line in file */
 >     copy each line into the newly malloc()ed space
 >     point a (char**) to the newly malloc()ed space
 >   }
 >
 >so now I should have "lines" number of pointers to pointers to char,
 >each one pointing to 90 bytes containing a line in the file.
 >
 >So, I call qsort(array[0], lines, 90, compare)
 >where compare is my comparison function -- prepared as discussed
 >in the FAQ.  Now all I get are core dumps during the call to qsort().
 >:-)

You need a pointer to the first element of the array, not the first element
itself. You should be calling it qsort(array, ... );

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