C-Kurs/Bus Error/Musterlösung: Unterschied zwischen den Versionen
Mario (Diskussion | Beiträge) K Musterlösung |
Mario (Diskussion | Beiträge) K Freizeile ohne Freizeichen .... |
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| Zeile 4: | Zeile 4: | ||
int an_int; | int an_int; | ||
}; | }; | ||
struct header { | struct header { | ||
short id; | short id; | ||
char data[0]; | char data[0]; | ||
}; | }; | ||
struct header * maker( int size ) { | struct header * maker( int size ) { | ||
return (struct header *)malloc( sizeof( struct header ) + size ); | return (struct header *)malloc( sizeof( struct header ) + size ); | ||
} | } | ||
int main( void ) { | int main( void ) { | ||
struct header * a_headered_thing = maker( sizeof( struct thing ) ); | struct header * a_headered_thing = maker( sizeof( struct thing ) ); | ||
struct thing * a_thing = (struct thing *)&(a_headered_thing->data[0]); | struct thing * a_thing = (struct thing *)&(a_headered_thing->data[0]); | ||
a_thing->an_int = 42; | a_thing->an_int = 42; | ||
} | } | ||
Version vom 6. September 2010, 14:56 Uhr
Der Bus Error wurde bereits in der VL erwähnt. Hier ein Quellcodeauszug aus [1], der ihn erzeugt.
struct thing {
int an_int;
};
struct header {
short id;
char data[0];
};
struct header * maker( int size ) {
return (struct header *)malloc( sizeof( struct header ) + size );
}
int main( void ) {
struct header * a_headered_thing = maker( sizeof( struct thing ) );
struct thing * a_thing = (struct thing *)&(a_headered_thing->data[0]);
a_thing->an_int = 42;
}