[NTLUG:Discuss] C pointer questions

[Rusty Haddock]

Paul Ingendorf wrote:
    >>From what I read in the question you are looking for the strings functions
    >
    >#include <string.h>
    >
    >char *a = " a test.", *b = "This is";
    >b = strcat( b, a );
    >printf(b);
    >
    >Should print:
    >This is a test

It's very doubtful this would work.  You're causing strcat() to exceed
the boundaries of what "b" is pointing to unless there's just happens
to be some user data area after the "This is" string.  This should
prevent the exception signal in many environments.  In others, the
string constants above could be linked to read-only memory and then
you're really up string creek. :-)

strcat() does not allocate new memory for its result. The assignment
of the return value of strcat() is rather superfulous.  The man page
for strcat(3), which isn't more than a large screen-full, explicitly
states this.  Nonetheless, this is bad technique.

	-Rusty-
-- 
   _____        Rusty Haddock  =  KD4WLZ  =  rusty at fe2o3.lonestar.org
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