I'm taking a class on C, and running into a segmentation fault. From what I understand, seg faults are supposed to occur when you're accessing memory that hasn't been allocated, or otherwise outside the bounds. 'Course all I'm trying to do is initialize an array (though rather large at that) Am I simply misunderstanding how to parse a 2d array? Misplacing a bound is exact
我正在上C课,并遇到分段错误。 根据我的理解,当您访问尚未分配的内存或超出边界时,seg故障应该会发生。 '我想要做的就是初始化一个数组(尽管它相当大) 我只是误解如何解析二维数组? 错误的绑定正是导致seg错误的原因 - 我在为此使用嵌套的for-loop时出错了吗? 教授提供了时钟功能,所以我希望这不是问题。 我在Cygwin上运行这个代码,这可能是问题吗? 源代码如下。 也使用c99标准。 要非常清楚:我正在
I'm not sure I quite understand the extent to which undefined behavior can jeopardize a program. Let's say I have this code: #include <stdio.h> int main() { int v = 0; scanf("%d", &v); if (v != 0) { int *p; *p = v; // Oops } return v; } Is the behavior of this program undefined for only those cases in which v is nonzero, or is it und
我不确定我是否理解未定义的行为会危害程序的程度。 假设我有这样的代码: #include <stdio.h> int main() { int v = 0; scanf("%d", &v); if (v != 0) { int *p; *p = v; // Oops } return v; } 该程序的行为是否仅针对v为非零的情况而未定义,或者即使v为零也未定义? 我想说,只有当用户插入任何不同于0的数字时,行为才是未定义的。毕竟,如果违规代码段没有实际
I think the question says it all. An example covering most standards from C89 to C11 would be helpful. I though of this one, but I guess it is just undefined behaviour: #include <stdio.h> int main( int argc, char* argv[] ) { const char *s = NULL; printf( "%cn", s[0] ); return 0; } EDIT: As some votes requested clarification: I wanted to have a program with an usual programming
我认为这个问题说明了一切。 涵盖从C89到C11的大多数标准的例子会很有帮助。 我虽然这一个,但我想这只是未定义的行为: #include <stdio.h> int main( int argc, char* argv[] ) { const char *s = NULL; printf( "%cn", s[0] ); return 0; } 编辑: 正如一些投票要求澄清的那样:我想要一个有通常编程错误的程序(我能想到的最简单的就是一个段错误),这是保证(通过标准)中止。 这与最小的段落问题有些
Using gprof 2.28 and gcc 6.3.0 in Ubuntu 17.04 on a variety of sample programs I get empty output for every category. If I run gprof -i on one example program I get: 1 histogram record 2 call-graph records 0 basic-block count records My compilation looks something like this: cc -g -c sem_test.c -pg cc -o sem_test sem_test.o -lpthread -pg Or this: gcc -g3 -O0 -Wall -std=gnu99 -pg -fprofile-a
在各种示例程序中使用Ubuntu 17.04中的gprof 2.28和gcc 6.3.0,我得到了每个类别的空输出。 如果我在一个示例程序上运行gprof -i,我会得到: 1 histogram record 2 call-graph records 0 basic-block count records 我的编译看起来像这样: cc -g -c sem_test.c -pg cc -o sem_test sem_test.o -lpthread -pg 或这个: gcc -g3 -O0 -Wall -std=gnu99 -pg -fprofile-arcs -fno-inline -fno-reorder-functions sem_test.c -o
I have a gprof "flat profile" output which lists all my functions, including static functions. But, the "calls", "self ms/call", and "total ms/call" columns are all empty for the functions declared as "static". I want to see the data for these functions as well; they are actually far more interesting to me than the public functions in the modul
我有一个gprof“flat profile”输出,它列出了我所有的功能,包括静态功能。 但是,对于声明为“静态”的函数,“调用”,“自我ms /调用”和“总ms /调用”列全部为空。 我也想看看这些功能的数据; 它们实际上比模块中的公共功能更有趣。 例如: % cumulative self self total time seconds seconds calls ms/call ms/call name 55.32 3.38 3.38
I thought of learning gprof.so i started with a simple program. I have written a small program in c below: #include<stdio.h> #include<unistd.h> void hello(void); int main() { hello(); return 0; } void hello() { int i; for(i=0; i<60; i++) { sleep(1); printf("hello worldn"); } } i compiled my program using -pg option. and i executed it to make sure that its w
我想到学习gprof.so我开始了一个简单的程序。 我在下面的c中写了一个小程序: #include<stdio.h> #include<unistd.h> void hello(void); int main() { hello(); return 0; } void hello() { int i; for(i=0; i<60; i++) { sleep(1); printf("hello worldn"); } } 我使用-pg选项编译我的程序。 我执行它来确保它的工作正常。 然后我做了 gprof -f hello a.out > gout 这给我创建
I had some experience lately with function pointers in C. So going on with the tradition of answering your own questions, I decided to make a small summary of the very basics, for those who need a quick dive-in to the subject. Function pointers in C Let's start with a basic function which we will be pointing to: int addInt(int n, int m) { return n+m; } First thing, let's defin
我最近在C中使用了函数指针。 因此,继续回答您自己的问题的传统,我决定对那些需要快速介入该主题的人做一个基本的小结。 C中的函数指针 我们先来看一个我们将要指出的基本功能: int addInt(int n, int m) { return n+m; } 首先,让我们定义一个指向一个函数的指针,它接收2个int并返回一个int : int (*functionPtr)(int,int); 现在我们可以安全地指向我们的功能: functionPtr = &addInt; 现在我们有了
Getting error while authorising an user ....enter image description here this is my code . public partial class facebook : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (Request["code"] != null && Page.IsPostBack) { checkauthorization(); } } protected void btnpost_Click(object sender, EventArgs e) { checkauthorization();
在授权用户的同时获取错误....在这里输入图片描述 这是我的代码。 public partial class Facebook:System.Web.UI.Page {protected void Page_Load(object sender,EventArgs e){if(Request [“code”]!= null && Page.IsPostBack){checkauthorization(); }} protected void btnpost_Click(object sender, EventArgs e) { checkauthorization(); } public void checkauthorization()
error on this line "message.To.Add(strCommandText);" when I try to take the email data from the database to send an email. public partial class beforeLogin_Auto_StaffPage : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void btnApprove_Click(object sender, EventArgs e) { string approve = "Approve"; string strConnectionString = Config
错误在这一行“message.To.Add(strCommandText);” 当我尝试从数据库中接收电子邮件数据以发送电子邮件时。 公共部分类之前Login_Auto_StaffPage:System.Web.UI.Page {保护无效Page_Load(对象发件人,EventArgs e){ } protected void btnApprove_Click(object sender, EventArgs e) { string approve = "Approve"; string strConnectionString = ConfigurationManager.ConnectionStrings["ChadBankConnectionStri
I am very new to VS for web applications and modules, I am trying to run/debug a http module so I followed this helpful tutorial: https://dotnetcodr.com/2015/07/10/how-to-register-a-custom-http-module-in-your-net-web-application/ and I got to debug his test module inside my sample WebApplication. Now I linked my module inside that sample WebApplication, I edited the Web.config replacing t
对于Web应用程序和模块,我对VS非常陌生, 我试图运行/调试一个http模块,所以我遵循这个有用的教程: https://dotnetcodr.com/2015/07/10/how-to-register-a-custom-http-module-in-your-net-web-application/ 我在示例WebApplication中调试了他的测试模块。 现在我将模块链接到示例WebApplication中,我编辑了替换此Web.config的代码 : <add name="DescriptiveNameOfModule" type="HttpModuleTestApplication.Mo