fgets 函数的问题

Question

这里我使用 fgets() 获取用户输入的几个字符串，它从未出现在输出中：

#include <stdio.h>

int main() {
    char color[20];
    char pluraNoun[20];
    char celebrity[20];

    printf("Enter a color: ");
    scanf("%s", color);
    printf("Enter a plural noun: ");
    scanf("%s", pluraNoun);
    printf("Enter a celebrity: ");

    fgets(celebrity, 20, stdin);

    printf("Roses are %s\n", color);
    printf("%s are blue\n", pluraNoun);
    printf("I love %s\n", celebrity);
    return 0;
}

Answer 1

不要混用 scanf() 和 fgets() 或如手册页所述：

It is not advisable to mix calls to input functions from the stdio library with low-level calls to read(2) for the file descriptor associated with the input stream; the results will be undefined and very probably not what you want.

这是一个 fgets() 版本：

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

#define LEN 20

char *strip(char *s) {
    size_t n = strlen(s);
    if(n && s[n-1] == '\n') s[n-1] = '[=10=]';
    return s;
}

int main() {
    char color[LEN];
    char pluraNoun[LEN];
    char celebrity[LEN];

    printf("Enter a color: ");
    fgets(color, LEN, stdin);

    printf("Enter a plural noun: ");
    fgets(pluraNoun, LEN, stdin);

    printf("Enter a celebrity: ");
    fgets(celebrity, LEN, stdin);

    printf("Roses are %s\n", strip(color));
    printf("%s are blue\n", strip(pluraNoun));
    printf("I love %s\n", strip(celebrity));
    return 0;
}

您想检查 fgets() 的 return 值以确保您的程序在 EOF.

上做一些合理的事情

fgets 函数的问题

Problems with fgets function

c

fgets