简单的字符串操作，包括输入输出、求长度、字符串比较和复制等。

#include <stdio.h>
#define MAXBUFF 128
int main(void) {
    char c[] = "012345";
    char line[MAXBUFF];
    int lcv;
    int cmp;
    printf("sizeof(c)= %d\n", sizeof(c));
    printf("sizeof(line)= %d\n", sizeof(line));
    for (lcv=0; lcv<=strlen(c); lcv++)
        printf("c[lcv]= %d = %c\n",c[lcv],c[lcv]);
    printf("Please enter a string : ");
    scanf("%s",line);
    printf("strlen(line) = %d\n", strlen(line));
    printf("line = [%s]\n",line);
    cmp = strcmp(c,line);
    if(cmp<0)
        printf("%s is less than %s\n", c, line);
    else if (c==0)
        printf("%s is equal to %s\n", c, line);
    else
        printf("%s is greater than %s\n", c, line);
    strcpy(line,c);  // 将字符串 c 复制到 line
    cmp = strcmp(c,line);
    if(cmp<0)
        printf("%s is less than %s\n", c, line);
    else if (cmp==0)
        printf("%s is equal to %s\n", c, line);
    else
        printf("%s is greater than %s\n", c, line);
}

输出结果：