How to implement guide with string comparison function returning unexpected results in c
I'm confused about I tried several approaches but none seem to work. I'm working with a perplexing scenario with a custom string comparison function in C that seems to produce incorrect results under certain conditions. My implementation is supposed to check whether two strings are equal, but occasionally it reports unequal strings even when they appear the same. Here’s the code I’m currently using: ```c #include <stdio.h> #include <string.h> int custom_str_compare(const char *str1, const char *str2) { while (*str1 && *str2) { if (*str1 != *str2) { return 0; // Not equal } str1++; str2++; } return *str1 == *str2; // Both must be null for equality } int main() { const char *test1 = "hello"; const char *test2 = "hello"; const char *test3 = "helloworld"; printf("Comparing test1 and test2: %d\n", custom_str_compare(test1, test2)); // Should be 1 printf("Comparing test1 and test3: %d\n", custom_str_compare(test1, test3)); // Should be 0 return 0; } ``` I ran this code and expected `1` for `test1` and `test2`, and `0` for `test1` and `test3`, but it prints `1` for both comparisons in certain scenarios. After further investigation, I discovered that when I pass strings that are allocated dynamically and contain trailing whitespace, the comparison fails. For example: ```c const char *test4 = malloc(6); sprintf((char*)test4, "hello\0"); // Dynamically allocated string ``` When comparing `test1` with `test4`, I see unexpected results, even though visually they seem identical. I suspect this has to do with how I’m handling the strings in memory, or the way the null terminators are being processed. Could this be due to an scenario with dynamic memory allocation or string termination? I’ve also checked for memory leaks, so I’m confident there are no overwrites. What am I missing here? Any guidance on how to ensure accurate string comparisons, especially with dynamically allocated strings would be greatly appreciated. For context: I'm using C on Ubuntu. What's the best practice here?