【发布时间】：2011-07-27 07:35:22
【问题描述】：
我多年来一直在研究这个程序，但不知道为什么它不起作用。我有理由确定它做的一切都是正确的，但实际上它并没有工作，它只是在打印第一个提示后无限期地挂起，我只是不知道为什么。我现在几乎无能为力了，所以如果有人能指出我做错了什么，我将非常感激......
它是 C99，您需要 mhash 库来编译它（用于 CRC32 计算）。它非常便携，但我是在 Linux 上开发的。 不要在虚拟机中运行！
#define _BSD_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <mhash.h>
/* WARNING: Do not debug this program. Halting on breakpoints at the wrong
* time can be extremely hazardous. YOU HAVE BEEN WARNED. */
/* Structures used to define our layout. Note the careful use of volatile;
* we don't want the compiler optimising away part of the invocation. */
typedef struct
{
const char name[7]; /* sigil at focus */
volatile int target; /* summoning point */
volatile char invocation; /* current char of invocation */
} focus_t;
typedef struct node
{
const char name[4]; /* name of node */
focus_t* center; /* points to the evocation focus */
struct node* cw; /* clockwise binding ring */
struct node* ccw; /* counterclockwise binding ring */
struct node* star; /* next node of star */
const char* linkname; /* name of star linkage */
volatile uint32_t angel; /* protective angel for this node */
} node_t;
/* The pentacle nodes are circularly linked in both directions to form
* a binding perimeter. In addition, they are singly linked to form a
* classic 'daemon trap' five-pointed star. Each node points towards the
* evocation focus (but not the other way around!) to enforce the geometry
* we want. The design is based heavily on the Pentagram of Solomon. */
struct
{
focus_t focus;
node_t node[5];
}
S =
{
/* None of the symbols for the pentacle are in Unicode. So we have to make
* do with Latin transcriptions. */
.focus = { "SOLUZEN", 0 },
.node = {
[0] = { "TE", &S.focus, &S.node[1], &S.node[4], &S.node[2], "BELLONY" },
[1] = { "TRA", &S.focus, &S.node[2], &S.node[0], &S.node[3], "HALLIY" },
[2] = { "GRAM", &S.focus, &S.node[3], &S.node[1], &S.node[4], "HALLIZA" },
[3] = { "MA", &S.focus, &S.node[4], &S.node[2], &S.node[0], "ABDIA" },
[4] = { "TON", &S.focus, &S.node[0], &S.node[3], &S.node[1], "BALLATON" }
}
};
/* Name of spirit to summon --- rot13'd for safety.
* (#65 from Crowley's translation of SHEMHAMPHORASH.)
* This is Andrealphus, he that has dominion over menusuration, astronomy and
* geometry. He seems fairly non-threatening. */
const char spiritname[] = "NAQERNYCUHF";
int rot13(int c) { return 'A' + (((c - 'A') + 13) % 26); }
/* We invoke the following names around the circle as a protective measure.
* Strictly these should be in Hebrew script, but as the computer is a dumb
* instrument we're relying on the symbolism rather than the actual literal
* meaning themselves. Plus, working in RTL is a pain. */
const char* angels[] = {
"Kether", "Eheieh", "Metatron", "Chaioth ha-Qadesh",
"Rashith ha-Gilgalim", "Chokmah", "Jah", "Ratziel", "Auphanim",
"Masloth", "Binah", "Jehovah Elohim", "Tzaphkiel", "Aralim",
"Shabbathai", "Chesed", "El", "Tzadkiel", "Chasmalim", "Tzadekh",
"Geburah", "Elohim Gibor", "Khamael", "Seraphim", "Madim",
"Tiphareth", "Eloah Va-Daath", "Raphael", "Malachim", "Shemesh",
"Netzach", "Jehovah Sabaoth", "Haniel", "Elohim", "Nogah", "Hod",
"Elohim Sabaoth", "Michael", "Beni Elohim", "Kokab", "Yesod",
"Shaddai El Chai", "Gabriel", "Cherubim", "Levanah"
};
const int angelcount = sizeof(angels)/sizeof(*angels);
/* Place the next angel on the pentacle. */
static void updatepentacle()
{
static int angelnode = 0;
static int angelindex = 0;
const char* angel = angels[angelindex++];
angelindex %= angelcount;
/* Hash the angel's name to reduce its essence to 32 bits (which lets us
* copy the angel bodily into the pentacle node. */
uint32_t angelhash;
MHASH td = mhash_init(MHASH_CRC32);
mhash(td, angel, strlen(angel));
mhash_deinit(td, &angelhash);
S.node[angelnode].angel = angelhash;
angelnode = (angelnode + 1) % 5;
}
int main(int argc, const char* argv[])
{
/* Lock the evocation into memory, to prevent it from being paged out
* while the spirit has manifested --- which would be bad. */
int e = mlock(&S, sizeof(S));
if (e != 0)
{
fprintf(stderr, "Unable to lock evocation, refusing to run\n");
exit(1);
}
/* Actually perform the invocation: continually cycle the spirit's
* name into the evocation focus (while maintaining our pentacle
* integrity!) until something shows up in the target of the
* evocation focus. */
printf("Summoning...\n");
do
{
for (int i = 0; i < sizeof(spiritname)-1; i++)
{
S.focus.invocation = rot13(spiritname[i]);
updatepentacle();
usleep(100); /* don't CPU-starve our spirit */
}
}
while (S.focus.target == 0);
printf("Summoning successful! %d\n", S.focus.target);
/* Our spirit's arrived! Dismiss it immediately by using a null
* invocation. Keep going until the evocation focus remains empty.
* FIXME: a particularly mean spirit might find a way to hide. Until
* we can sort this out, only summon relatively benign ones. This is
* probably safe anyway, as when the process terminates the spirit's
* address space will be nuked, taking the spirit with it. */
printf("Dismissing...\n");
do
{
S.focus.target = 0;
for (int i = 0; i < 1000; i++)
{
S.focus.invocation = 0;
updatepentacle();
}
}
while (S.focus.target != 0);
printf("Done.\n");
return 0;
}
顺便说一句，不应该有goetic标签吗？
编辑：对不起，我没有早点回来 --- 昨晚我发布了我的查询后，我进行了更多测试，然后我的电脑开始发出有趣的燃烧气味，但并没有消失当我把它关掉时，我花了整晚的时间把它拆下来，试图找出哪个部分有问题。 （什么也没找到。）我要睡一会儿再找你。感谢您的回复！
编辑：我从一家网吧发帖。我的房子被烧毁了。没有时间发布更多内容，但必须警告您：请勿以任何理由运行此程序！真的！不开玩笑！现在得走了，一定要找个避难所---
编辑： ???????????? ?????????????????????????????? ??????????????? ？？？？？？？？？？？？ ？？？？？？？？？ ???????????????????????????????????? ？？？？？？？？？ ？？？？？？？？？ ?????????????????????????????????????????????.
【问题讨论】：
-
使用 HTML 编码你的天使名字，并在召唤过程中使用正则表达式解析它。 HTH，手
-
/* This is probably safe anyway, as when the process terminates the spirit's address space will be nuked, taking the spirit with it. */无价的stackoverflow时刻 -
C 不够邪恶，不足以召唤恶魔。您需要使用 C++（或者可能是 Visual Basic）来完成此类任务。
-
您是否尝试过在
gdb中运行它，然后在卡住时按Ctrl-C，以便找出它在程序中的位置？注释掉对updatepentacle的调用怎么样？用胡言乱语替换精神名称，这样你就不会在测试过程中意外召唤它。 -
此程序导致无法言说的行为。