c - 字符串示例未按预期运行

Question

我正在学习 C，并且一直在学习“Head First C”这本书。我找到了一个示例，其中这是结果代码:

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


char tracks[][80] = {
    "I left my heart in Harvard Med School",
    "Newark, Newark - A wonderful town",
    "Dancing with a Dork",
    "From here to maternity",
    "The girl from Iwo Jima", 
};


void find_track(char search_for[])
{
    int i;
    for(i = 0; i < 5; i++) {
        if (strstr(tracks[i], search_for))
            printf("Track %i: '%s'\n", i, tracks[i]);
    }
}


int main()
{
    char search_for[80];
    printf("Search for: ");
    fgets(search_for, 80, stdin);
    find_track(search_for);
    return 0;
}

我已经进行了双重、三重和四重检查。此代码与书中的示例完全相同。起初我自己制作了它，这样我就不会只是复制而不学习，但是当我不工作时，我会直接复制它以确保。该代码请求一个字符串，然后打印包含您给它的字符串的所有轨道。在书中，当示例代码运行时，给出的字符串是“town”，代码打印“Newark, Newark - A wonderful town”。但是，当我做完全相同的事情时，它只打印一个换行符。

我怎么强调都不为过，这段代码与书中的代码完全相同，但行为不同。有人能看出原因吗？

Answer 1

问题出在这条语句上

fgets(search_for, 80, stdin);

函数fgets 在字符串中包含换行符。您必须将其从字符串中删除。例如

size_t n = strlen( search_for );

if ( n != 0 && search_for[n-1] == '\n' ) search_for[n-1] = '\0';

来自 C 标准

说明

2 The fgets function reads at most one less than the number of characters specified by n from the stream pointed to by stream into the array pointed to by s. No additional characters are read after a new-line character (which is retained) or after end-of-file. A null character is written immediately after the last character read into the array.