在C中的txt文件中搜索单词答案

【问题标题】：Searching words in txt file in C在C中的txt文件中搜索单词
【发布时间】：2019-11-01 17:46:26
【问题描述】：

如何让我的程序读取文本文件并将文本文件中的单词与我在数组中定义的单词进行比较并打印一条消息。我认为主要问题是 for 循环，因为我不确定它是否正确迭代。这是我的代码：

define MAX_SIZE 1000

int main()
{
    FILE * yourfile;

    char  as_array[MAX_SIZE];
    char name[20];
    const char * keywords[]={"if", "else", "return", "switch", "case", "default", "for", "do", "while", 
                             "break", "continue", "struct", "typedef", "union", "enum", "sizeof", "int", "float", "double", 
                             "void", 
                             "extern",
                             "signed", "unsigned", "long", "short", "static", "const",  "goto", "auto", "register", "volatile"};
    printf("Please write the file you want to open: \n ");
    scanf("%s", name);

    int number_of_keywords = sizeof(keywords)/sizeof(keywords[0]);

    //fopen opens the file; exits with error if the file cannot be opened
    if ((yourfile = fopen(name, "r"))== NULL){
        printf("Could not open file: %s", name);
        exit(1);
    }
    else printf("Your file has been successfully opened!\n");

    while(!feof(yourfile)){
        fgets(as_array, MAX_SIZE, yourfile);
        printf("%s\n", as_array);
        char x = gets(as_array);

        for(int i = 0 ; i<number_of_keywords; ++i){
            if(keywords[i]== x){
                printf("I found word %s\n", keywords[i]);
            }
        }
        return 0;
    }
}

【问题讨论】：

欢迎来到 Stack Overflow！ Why while(!feof(file)) is always wrong
keywords[i]== x 应该是strcmp(keywords[i], x) == 0
这条线是干什么用的：char x = gets(as_array);？那就是从标准输入中读取一行，并用它覆盖as_array。
Why is “while ( !feof (file) )” always wrong?
“无法打开文件”是错误消息的典型示例。为什么文件打不开？是权限问题吗？让系统给你一个理由。 if ((yourfile = fopen(name, "r"))== NULL){ perror( name ) ...

标签： c file

【解决方案1】：

假设你的文本文件是 test.txt 并且包含

if
else
return
switch
case

然后这段代码可以工作，抱歉我重新格式化了一下，0 shd 是\o，我硬编码了文件名，但你会明白的，玩得开心。

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

#define MAX_SIZE 1000

    int main()
    {
        FILE * yourfile;
        int i;
        int number_of_keywords;
        char string[200];
        char  as_array[MAX_SIZE];
        char name[20]="test.txt";
        const char * keywords[]={"if", "else", "return", "switch", "case", "default", "for", "do", "while", 
                                 "break", "continue", "struct", "typedef", "union", "enum", "sizeof", "int", "float", "double", 
                                 "void", 
                                 "extern",
                                 "signed", "unsigned", "long", "short", "static", "const",  "goto", "auto", "register", "volatile"};
      //  printf("Please type file name to open: \n ");
      //  scanf("%s", name);

        number_of_keywords = sizeof(keywords)/sizeof(keywords[0]);

        //fopen opens the file; exits with error if the file cannot be opened
        if ((yourfile = fopen(name, "r"))== NULL){
            printf("Could not open file: %s", name);
            exit(1);
        }
        else printf("Your file has been successfully opened!\n");


      while(  fgets( string, 200 , yourfile))
      {
        // problem : fgets grabs \n
        // remove it
        string[strlen(string)-1]=0;    
        printf( string);
        getchar();
        for( i=0 ; i<number_of_keywords; i++)
        {
         if(!strcmp(keywords[i], string))
                    printf("I found word %s\n", keywords[i]);
        }
       } 

         fclose(yourfile);
            return 0;

    }

【讨论】：