programming-examples/c/Basic/What happens if you free a pointer twice.c

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2019-11-18 14:44:36 +01:00
#include <stdio.h>
#include <conio.h>
int main(int argc, char** argv) {
char** new_argv1;
char** new_argv2;
new_argv1 = calloc(argc+1, sizeof(char*));
free(new_argv1);
/* freed once */
new_argv2 = (char**) calloc(argc+1, sizeof(char*));
if (new_argv1 == new_argv2) {
/* new_argv1 accidentally points to freeable memory */
free(new_argv1);
/* freed twice */
} else {
free(new_argv2);
}
new_argv1 = calloc(argc+1, sizeof(char*));
free(new_argv1);
/* freed once again */
return 0;
}