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From: joshua@athertn.Atherton.COM (Flame Bait)
Newsgroups: comp.unix.questions
Subject: is struct stat buf.st_size always correct?
Message-ID: <21501@joshua.athertn.Atherton.COM>
Date: 11 Apr 90 23:36:05 GMT
Reply-To: joshua@Atherton.COM (Flame Bait)
Organization: Atherton Technology, Sunnyvale, CA
Lines: 31

I have a simple routine which uses stat() to find the size of a file,
then mallocs space for it, and then freads the whole file into a string.
Under SunOS 3.5 (mostly 4.2BSD) it seemed to work fine, but I did not
use it much.  Under SunOS 4.0.3 (mostly 4.3BSD) I sometimes end up with
extra `\377' characters at the end of the string.  It looks like the whole
file is there, but with two extra characters as well.

Is it possible that the st_size is rounded up to the nearest 4 bytes,
or something like that? 

The routine is similar to this one:

int eatfile(name, place) char *name ; char **place ;
{
    struct stat buf ;
    int size ;
    FILE *fp ;
    int s ;

    /* actions */                     /* error checking */
    s = stat(name,&buf) ;             if (s == -1) return -1 ;
    size = buf.st_size ;
    *place = malloc((unsigned)size) ; if (!*place) return -2;
    fp = fopen(name,"r") ;            if (!fp) { free(*place) ; return -3 ; }
    s = fread(*place,1,size,fp) ;     if (!s) { free(*place) ; return -4 ; }
    s = fclose(fp) ;                  if (s==EOF) { free(*place); return -5; }
    return size ;
}

Joshua Levy                          joshua@atherton.com  home:(415)968-3718
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