7：locate.c 这个程序是为了输出16MB和1GB在内存中所在的位置和转换为unsigned long型的内容，并且不断增加内存，然后再输出p1,p2,p3,p4 ，以及useless,exit，malloc等等所在的地址和内容 代码为：
#include <stdlib.h> #include <stdio.h> #include <unistd.h> static void show_pointer(void *p, char *descr) { // printf("Pointer for %s at %p\n", descr, p); printf("%s\t%p\t%lu\n", descr, p, (unsigned long) p); } char big_array[1L<<24]; /* 16 MB */ //char huge_array[1L<<31]; /* 2 GB */ char huge_array[1L<<30];/* 1 GB */ int global = 0; int useless() { return 0; } int main () { void *p1, *p2, *p3, *p4; int local = 0; p1 = malloc(1L << 28); p2 = malloc(1L << 8); //p3 = malloc(1L << 32); p3 = malloc(1L << 16); p4 = malloc(1L << 8); show_pointer((void *) big_array, "big array"); show_pointer((void *) huge_array, "huge array"); show_pointer((void *) &local, "local"); show_pointer((void *) &global, "global"); show_pointer((void *) p1, "p1"); show_pointer((void *) p2, "p2"); show_pointer((void *) p3, "p3"); show_pointer((void *) p4, "p4"); show_pointer((void *) useless, "useless"); show_pointer((void *) exit, "exit"); show_pointer((void *) malloc, "malloc"); return 0; } /* gec@ubuntu:/mnt/hgfs/share/csapp_code$ gcc locate.c gec@ubuntu:/mnt/hgfs/share/csapp_code$ ./a.out big array 0x4804a060 1208262752 huge array 0x804a060 134520928 local 0xbfcc9fdc 3217858524 global 0x804a044 134520900 p1 0xa7545008 2807320584 p2 0x49a67008 1235644424 p3 0x49a67110 1235644688 p4 0x49a77118 1235710232 useless 0x80484b6 134513846 exit 0x8048370 134513520 malloc 0x8048350 134513488 */