segmentation-fault

问题 I'm trying to make an own list-class which is of a fixed size and can store integers. Just for learning purposes. This is how I do it: I have a struct called Item which holds the data (the integer to store), and a pointer to the next item in the list. When the list gets initialized I first add x amount of empty Items to the list. The address of item declared in iteration (n-1) is stored in a buffer, so that the address of the item in iteration n, can be set as next for the item in the

问题 I am implementing a function to recursively reverse a linked-list, but getting seg-fault. typedef struct _node { int data; struct _node *next; } Node, *NodeP; NodeP recursiveReverseList(NodeP first){ if(first == NULL) return NULL; if(first->next == NULL) return first; NodeP rest = recursiveReverseList(first->next); rest->next = first; first->next = NULL; return first; } Can you please help? P.S. The iterative version is working fine though. Its not homework. Just practicing C. Thank you all :

问题 My actual problem is a lot more complicated and it seems extremely difficult to give a short concrete example here to reproduce it. So I am posting here a different small example that may be relevant, and its discussion may help in the actual problem as well: // A: works fine (prints '2') cout << std::get <0>(std::get <1>( std::forward_as_tuple(3, std::forward_as_tuple(2, 0))) ) << endl; // B: fine in Clang, segmentation fault in GCC with -Os auto x = std::forward_as_tuple(3, std::forward_as

问题 What causes the output "Hello" when I enable -O for gcc ? Shouldn't it still segfault (according to this wiki) ? % cat segv.c #include <stdio.h> int main() { char * s = "Hello"; s[0] = 'Y'; puts(s); return 0; } % gcc segv.c && ./a.out zsh: segmentation fault ./a.out % gcc -O segv.c && ./a.out Hello 回答1: It's undefined behavior (might crash, might not do anything , etc) to change string literals. Well explained in a C FAQ. 6.4.5/6 It is unspecified whether these arrays are distinct provided

问题 After 2 days battling, I try asking help here. I'm using unixODBC (2.2.11) to work with DB2 (iSeries) and PHP (5.3) on a CentOS 5.4 server. I guess it's since the upgrade of PHP from 5.1 to 5.3, I get PHP to segfault on certain queries. After some investigation, I discovered the problem appears on some queries with long char fields, for example with this table : TABLE ( CONTRACTID NUMERIC, SOMETEXT CHAR(583) ) This simple piece of code provokes the segfault : try { $conn = new PDO("odbc:".

问题 I currently use ASIHTTPRequest for synchronous requests I recently refactored my code to comply with ARC and omit the ASIHTTPRequest class using the compiler flag -fno-objc-arc I have a _mh_execute_header SIGSEGV crash when I use any type of optimization While turning off all optimization allows my app to run - I need to be able to optimize the app using the iOS default settings which use Fastest, Smallest [-Os] Since this is a memory related issue and since the only manually managed memory

问题 I'll try to make things clear. Here is my struct: struct scopeList{ int id; list<int> internal_list; }; typedef struct scopeList scopeList_T; Here is the code that gives me the segmentation. int main(){ scopeList_T* t1 = (scopeList_T*) malloc(sizeof(scopeList_T)); t1->id = 5; //works fine t1->internal_list.push_front(5); //segmentation fault } Since I am allocating memory and accessing id is fine, why is does this give me a segmentation fault? Do I have to do something special to the list

问题 I posted a previous question "Seg Fault when using std::string on an embedded Linux platform" where I got some very useful advise. I have been away on other projects since then and have recently returned to looking at this issue. To reiterate, I am restricted to using the arm-linux cross compiler (version 2.95.2) as this is what is supplied and supported by the embedded platform vendor. I understand that the issue is likely because the stdlib is very old, and not particularly thread safe. The

问题 The segmentation fault error disappears after commenting out the scanf loop. Why is that loop giving me a segmentation fault? char** nameArray = malloc(numNames * sizeof(char *)); for(i =0; i< 10; i++) { nameArray[i] = malloc(25 * sizeof(char)); } for (i = 0; i< numNames; i++) { scanf("%s", &nameArray[i]); } for (i =0; i<numNames; i++) { free(nameArray[i]); } 回答1: First you need to change for(i =0; i< 10; i++) { to for(i =0; i< numNames; i++) { as you need to create enough entries. Also you

问题 I've got a Galaxy Nexus and today it started to give me a Segmentation fault error when deploying to it: [2011-12-07 16:19:17 - Flinders Lite] Android Launch! [2011-12-07 16:19:17 - Flinders Lite] adb is running normally. [2011-12-07 16:19:17 - Flinders Lite] Performing com.istudentgroup.flinders.lite.activity.MainMenuActivity activity launch [2011-12-07 16:19:20 - Flinders Lite] Uploading Flinders Lite.apk onto device '0146914B19021011' [2011-12-07 16:19:23 - Flinders Lite] Installing