lib-xmem

a C library with functions to handle memory management with out-of-memory handling

C API

The library only provides the following functions:

void* xmalloc(size_t size);
void* xcalloc(size_t nmemb, size_t size);
void* xrealloc(void* ptr, size_t size);
void xfree(void* p);
const char* xstrdup(const char* s);

Usage

xmalloc

#include <xmem.h>

int main() {
    char* p = xmalloc(10);
    xfree(p);
    return 0;
}

This code will allocate 10 bytes of memory and free it. If the allocation fails, the program will call exit() exit with an error message.

xcalloc

#include <xmem.h>

int main() {
    char* p = xcalloc(10, sizeof(char));
    xfree(p);
    return 0;
}

This code will allocate 10 bytes of memory and free it. If the allocation fails, the program will call exit() exit with an error message.

xrealloc

#include <xmem.h>

int main() {
    char* p = xmalloc(10);
    p = xrealloc(p, 20);
    xfree(p);
    return 0;
}

This code will allocate 10 bytes of memory, reallocate it to 20 bytes and free it. If the allocation fails, the program will call exit() exit with an error message.

xfree

#include <xmem.h>

int main() {
    char* p = xmalloc(10);
    xfree(p);
    return 0;
}

This code will allocate 10 bytes of memory and free it. If the allocation fails, the program will call exit() exit with an error message. The xfree function is safe to call with a NULL pointer in which case it will do nothing. After freeing the memory, the pointer is set to NULL in order to avoid double freeing and undefined behavior in case the pointer is used after being freed.

xstrdup

#include <xmem.h>

int main() {
    char* p = xstrdup("Hello, World!");
    xfree(p);
    return 0;
}

This code will allocate memory for the string "Hello, World!" and free it. If the allocation fails, the program will call exit() exit with an error message. It uses xmalloc internally to allocate memory for the string and strlen to get the length of the string. The caller is expected to free the memory allocated by xstrdup using xfree. The copying is done using memcpy and the string is null-terminated automatically. We used memcpy instead of strcpy to avoid buffer overflows and undefined behavior but you could use strcpy if you are sure that the string is null-terminated and know what you are doing. memcpy is handles unaligned memory very well.

Usage in C projects

• Just include the xmem.h header file in your C project and compile since it's a single-header library.

Contributing

If you want to contribute to this project and make it better, your help is very welcome. Contributing is also a great way to learn more and improve your skills. I'll be happy to help you with your contributions and any questions you may have.

License

This project is licensed under the MIT License - see the LICENSE file for details