👀 Views: 0 💬 Answers: 1 📅 Created: 2025-06-14

c string-manipulation strncpy buffer-overflow C

Can someone help me understand I've been researching this but I keep running into I've been banging my head against this for hours. I'm working on a personal project and I'm experiencing an scenario with the `strncpy` function in my C application where the destination string seems to get truncated unexpectedly, leading to incorrect string handling later in my code. I'm using GCC version 10.2 on a Linux system. Here's a simplified version of my code: ```c #include <stdio.h> #include <string.h> int main() { char dest[10]; const char *src = "Hello, World!"; strncpy(dest, src, sizeof(dest)); dest[sizeof(dest) - 1] = '\0'; // Ensure null termination printf("Dest: '%s'\n", dest); return 0; } ``` In this example, I expect `dest` to contain a truncated version of `src` (i.e., "Hello, Wor"). However, when I run it, it seems to print `Dest: 'Hello, Wor'`, but sometimes it shows unexpected junk characters or behaves inconsistently. I've tried different lengths in `strncpy`, and I always ensure that I null-terminate `dest` manually, but it still behaves erratically. I suspect it might be related to how I've set up the destination buffer or how I'm calculating the size, but I'm not sure what the best practice is here. Is there something I'm missing with the usage of `strncpy`, or is there a better alternative to handle string copying in C? Any insights would be greatly appreciated. What am I doing wrong? This is part of a larger application I'm building. How would you solve this? This is part of a larger desktop app I'm building. What am I doing wrong? This is part of a larger application I'm building. Is this even possible? I'm working in a Debian environment. Is there a better approach?