将未知长度的格式化数据写入字符串(C编程)

#include<stdio.h>
#include <stdlib.h>
#include<string.h>

int main() {
    char *str = NULL;
    int length = 0;

    // 动态分配内存
    str = (char *) malloc(1);
    if (str == NULL) {
        printf("Memory allocation failed\n");
        return 1;
    }
    str[0] = '\0';

    // 将未知长度的格式化数据写入字符串
    for (int i = 0; i < 5; i++) {
        char temp[50];
        sprintf(temp, "Hello %d\n", i);

        // 调整内存大小
        length += strlen(temp) + 1;
        str = (char *) realloc(str, length);
        if (str == NULL) {
            printf("Memory allocation failed\n");
            return 1;
        }

        // 连接字符串
        strcat(str, temp);
    }

    printf("Final string: %s", str);

    // 释放内存
    free(str);

    return 0;
}

Final string: Hello 0
Hello 1
Hello 2
Hello 3
Hello 4