safe_strn is a C library for safe string operation. It includes some basic string functions to prevent buffer overflow.
Firstly, compile the code with following command:
$ gcc lib/*.h lib/*.c test/*.h test/*.c example/*Then, run the executable file.
$ ./a.outAdd lib/ folder under your workspace and include the library as follows. You may need to give the relative path depending on where you put location.
#include "safe_string.h"
int main() {
char *src = "hello world";
char *new_str = (char *) malloc(sizeof(char) * 12); // Allocate memory for string
str_cpy(src, new_str, 11); // Copy src to new_str
int len = str_len(new_str); // Length of new_str
char *str1 = "abc";
char *str2 = "abc";
int res = str_cmp(str1, str2, 3, 3);
if (res < 0) {
printf("str1 less than str2\n"):
} else if (res > 0){
printf("str2 less than str1.\n");
} else {
printf("str1 and str2 are equal.\n"); // Prints "str1 and str2 are equal."
}
char *str = str_mk("create a new string.", 50); // Create a null-terminated string with maximum 50 length.
}Creates string by preventing potential buffer overflow. Guarantees putting null-terminator at the end of the string. Also, prevents buffer overflow which is caused by integer overflow.
char *str_mk(const char *str, size_t str_len);Copies the string from src to dst. You need to pass length of the string that you want to copy.
int str_cpy(const char *src, char *dst, size_t n));Returns the length of the string.
int str_len(const char *s);Concatenates the given strings. Returns the new length of the src.
int str_cat(char *src, const char *append, size_t src_size, size_t app_size);Compares the two given strings. If str1 less than str2, returns -1. If str2 less than str1, returns 1. And str1 and str2 are equal, then returns 0.
int str_cmp(const char *str1, const char *str2, size_t str1_size, size_t str2_size);