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   9 <title>section 7.7: Line Input and Output</title>
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  15 <H2>section 7.7: Line Input and Output</H2>
  16
  17 pages 164-165
  18 <p>To summarize,
  19 <TT>puts</TT> is like <TT>fputs</TT>
  20 except that the stream is assumed to be the standard output (<TT>stdout</TT>),
  21 <em>and</em> a newline (<TT>'\n'</TT>) is automatically appended.
  22 <TT>gets</TT> is like <TT>fgets</TT>
  23 except that the stream is assumed to be <TT>stdin</TT>,
  24 and the newline (<TT>'\n'</TT>) is deleted,
  25 <em>and</em> there's no way to specify the maximum line length.
  26 This last fact means that
  27 you
  28 almost never
  29 want
  30 to use <TT>gets</TT>
  31 at all:
  32 since you can't tell it how big the array it's to read into is,
  33 there's no way to guarantee
  34 that some unexpectedly-long input line
  35 won't overflow the array,
  36 with dire results.
  37 (When discussing the drawbacks of <TT>gets</TT>,
  38 it's customary to point out that the ``Internet worm,''
  39 a program that wreaked havoc in 1988
  40 by breaking into computers all over the net,
  41 was able to do so
  42 in part
  43 because a key network utility
  44 on many Unix systems
  45 used <TT>gets</TT>,
  46 and
  47 the worm was able to overflow the buffer
  48 in a particularly low, cunning way,
  49 with the dire result that
  50 the worm achieved superuser access to the attacked machine.)
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  60 This page by <a href="http://www.eskimo.com/~scs/">Steve Summit</a>
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