12???????C??????????

???????????? ???????[ 2012/9/7 9:56:58 ] ????????????

????5??free()????

?????????????????????????'freeze'????????????'zebra'?????????

#include<stdio.h>

int main(int argc?? char *argv[])
{
    char *ptr = (char*)malloc(10);

    if(NULL == ptr)
    {
        printf(" Malloc failed ");
        return -1;
    }
    else if(argc == 1)
    {
        printf(" Usage ");
    }
    else
    {
        memset(ptr?? 0?? 10);

        strncpy(ptr?? argv[1]?? 9);

        while(*ptr != 'z')
        {
            if(*ptr == '')
                break;
            else
                ptr++;
        }

        if(*ptr == 'z')
        {
            printf(" String contains 'z' ");
            // Do some more processing
        }

       free(ptr);
    }

    return 0;
}

????????????????????????????????“ptr”?????while?????“ptr”?洢????????????“zebra”???while????????????????????????free()??????????malloc()??????????“freeze”???“ptr”?洢????????while??????????????′???free()????????????????seg-fault?????????

????6?????_exit???

??????????????????У?atexit()????б???????????

#include<stdio.h>

void func(void)
{
    printf(" Cleanup function called ");
    return;
}

int main(void)
{
    int i = 0;

    atexit(func);

    for(;i<0xffffff;i++);

    _exit(0);
}