修剪C中的字符串

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

char *trim(char *str) {
    int start = strspn(str, " \t\n\r\f\v"); // 计算开头空白字符的数量
    int end = strlen(str) - 1;
    while (end >= 0 && isspace(str[end])) { // 计算结尾空白字符的数量
        end--;
    }
    str[end+1] = '\0'; // 添加字符串结束符
    return str + start; // 返回修剪后的字符串
}

int main() {
    char str[] = " \t\n  Hello, world! \t\n ";
    printf("Original string: %s\n", str);
    printf("Trimmed string: %s\n", trim(str));
    return 0;
}

Original string:     
    Hello, world!    
 
Trimmed string: Hello, world!