lang/C/the.ansi.c.programming.language/notes.accompany.ansi.c/sx10l.html

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   9 <title>section 7.8.5: Storage Management</title>
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  15 <H2>section 7.8.5: Storage Management</H2>
  16
  17 <p>The important thing to know
  18 about <TT>malloc</TT> and <TT>free</TT> and friends
  19 is to be careful when calling them.
  20 It is easy to abuse them,
  21 either by using more space than you ask for
  22 (that is, writing beyond the ends of an allocated block)
  23 or by continuing to use a pointer after the memory it points to has been freed
  24 (perhaps because you had several pointers to the same block of memory,
  25 and you forgot that when you freed one pointer
  26 they all became invalid).
  27 <TT>malloc</TT>-related bugs can be difficult and frustrating to track down,
  28 so it's good to use programming practices
  29 which help to assure that the bugs don't happen in the first place.
  30 (One such practice is to make sure that pointer variables are set to
  31 <TT>NULL</TT> when they don't point anywhere,
  32 and to occasionally check pointer values--for instance at
  33 entry to an important pointer-using function--to make sure
  34 that they're not <TT>NULL</TT>.)
  35 </p><p>As we mentioned on page 142 in section 6.5,
  36 it is no longer necessary
  37 (that is, in ANSI C)
  38 to cast <TT>malloc</TT>'s value to the appropriate type,
  39 though it doesn't hurt
  40 to do so.
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  50 This page by <a href="http://www.eskimo.com/~scs/">Steve Summit</a>
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