So it means if I declare a file pointer in the called function only, then it is treated as different variable for each thread? A file pointer in one thread will not be manipulated by operations going on in other thread..
There could be other conflicts. File pointers may point to the very same file. As twain said, code could help to locate your problem. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Stack Gives Back Safety in numbers: crowdsourcing data on nefarious IP addresses. Featured on Meta. Besides, there is no advantage in attempting to call the Bit compatibility subsystem, since Windows virtualises all such calls - trapping them with a handler than emulates DOS.
One of the banes of C is the lack of a reliable and reputable package manager that support a package versioning, b package download, c integration with build systems. Thankfully some projects have been coming out of the woodwork, but still the landscape is a bit grim. So what is the solution for this? How can i update the Mingw package of the Dev-C?
Collin laplace is nowhere to be seen,and there is no chance he is coming back to bloodshed. Bloodshed Dev C 4. Practice problems Quizzes. Fortunately, tools like Cee Studio , from our sponsor, provide new, easier ways to debug memory errors and buffer overflows. Cee Studio is a web-based compiler designed to make finding segfaults easy by providing instant and informative feedback on misuses of memory.
But even without specialized tools, finding problems with pointers is easier than you think. This tutorial assumes that you have a basic knowledge of pointers such as can be acquired by reading a pointer tutorial. It would help to be running a system that has a debugger such as GDB, or to at least have sufficient familiarity with GDB-like debuggers to understand the examples presented. What is a segmentation fault? When your program runs, it has access to certain portions of memory.
First, you have local variables in each of your functions; these are stored in the stack. Your program is only allowed to touch memory that belongs to it -- the memory previously mentioned. Any access outside that area will cause a segmentation fault. Segmentation faults are commonly referred to as segfaults. A fifth way of causing a segfault is a recursive function that uses all of the stack space.
On some systems, this will cause a "stack overflow" report, and on others, it will merely appear as another type of segmentation fault. The strategy for debugging all of these problems is the same: load the core file into GDB, do a backtrace, move into the scope of your code, and list the lines of code that caused the segmentation fault.
The core file contains all the information needed by GDB to reconstruct the state of execution when the invalid operation caused a segmentation fault. Program terminated with signal 11, Segmentation fault.
Some information about loading symbols 0 0xc in foo at t. This is a goldmine of information: we already know exactly where the problem happened and which pointer was involved. The pointer x is initialized to 0, equivalent to NULL in fact, NULL is a stand-in for 0 , and we know that it's a no-no to then try to access that pointer. But what if it weren't so obvious? Simply printing the value of the pointer can often lead to the solution.
The address 0x0 is invalid -- in fact, it's NULL. If you dereference a pointer that stores the location 0x0 then you'll definitely get a segmentation fault, just as we did. If we'd gotten something more complicated, such as execution crashing inside a system call or library function perhaps because we passed an uninitialized pointer to fgets , we'd need to figure out where we called the library function and what might have happened to cause a segfault within it.
Does this mean the library function did something wrong? It means that we probably passed a bad value to the function. To debug this, we need to see what we passed into strcat.
So let's see what function call we made that led to the segfault.
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