C - 从文本文件打印特定行

Question

我是编程新手，所以请保持友善。

目前我正在尝试编写一个程序，打开一个文本文件，读取两个单词，搜索文本文件，计算这两个单词出现的次数，然后最后打印第一个单词出现的第一行。

到目前为止，这就是我所做的:

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

FILE *infile;
char inputWord1[100], inputWord2[100], filename[100], wordInText[100], line[500]; 
int i, count, strComp, word1Count, word2Count, wordLen, lineCount; 
char c;

int main() { 
    printf("Enter the first word: "); 
    gets(inputWord1); 
    printf("Enter the second word: "); 
    gets(inputWord2); 
    printf("Enter the file name: "); 
    gets(filename); 

    infile = fopen(filename, "r"); 
    if(infile == NULL) { 
        printf("Error"); 
        exit(1); 
    } 

    word1Count = 0; word2Count = 0; lineCount = 1;
    while(fscanf(infile, "%s", wordInText) != EOF) { 
        wordLen = strlen(wordInText);
        for(i = 0; i < wordLen; i++) {
            if(wordInText[i] >= 65 && wordInText[i] <= 90) { 
                wordInText[i] = wordInText[i] + 32; 
            }
        }

        for(c = getc(infile); c != EOF; c = getc(infile)) {
            if(c == '\n') { 
                lineCount = lineCount + 1;
            }
        }

        strComp = strcmp(wordInText, inputWord1); 
        if(strComp == 0) { 
            word1Count++;
            if(word1Count == 1) { 
                for(int x = lineCount; x <= lineCount; x++) {
                    fgets(line, 500, infile); 
                    printf("%s\n", line);
                }
            }
        }
        strComp = strcmp(wordInText, inputWord2); 
        if(strComp == 0) { 
            word2Count++; 
        }
    }
    printf("Word 1 appears %d times\n", word1Count); 
    printf("Word 2 appears %d times\n", word2Count);
}

所以所有这些都有效，除了:

strComp = strcmp(wordInText, inputWord1); 
        if(strComp == 0) { 
            word1Count++;
            if(word1Count == 1) { 
                for(int x = lineCount; x <= lineCount; x++) {
                    fgets(line, 500, infile); 
                    printf("%s\n", line);
                }
            }
        }

最后一个 for 循环无法正常工作。它打印出\n 但不打印该行。我真的不知道为什么它不起作用。所有其他部件都工作正常。

如果有人对如何解决这个问题有任何想法，我将非常感激。请记住，我只知道基本的 C 函数，而且我还没有完全完成这个程序(仍然需要将输入的单词转换为小写)。

Answer 1

应该替换 gets 以避免缓冲区溢出 我使用了一些定义，当我们找到单词时，输入行将被复制并在最后打印。 文件逐行读取，每行逐字分割。 解析应该更新，例如允许多个空格，支持更多单词分隔符等...

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

#define WORD_LEN_MAX 100                                                       
#define LINE_LEN_MAX 500                                                       

int main() {                                                                   
    FILE *infile;                                                              
    char inputWord1[WORD_LEN_MAX], inputWord2[WORD_LEN_MAX];                   
    char filename[WORD_LEN_MAX];                                               
    char wordInText[WORD_LEN_MAX], line[LINE_LEN_MAX];                         
    char firsAppear[LINE_LEN_MAX];                                             
    int word1Count, word2Count, lineCount, i;                                  
    printf("Enter the first word: ");                                          
    gets(inputWord1);                                                          
    printf("Enter the second word: ");                                         
    gets(inputWord2);                                                          
    printf("Enter the file name: ");                                           
    gets(filename);                                                            


    infile = fopen(filename, "r");                                             
    if(infile == NULL) {                                                       
        printf("Error cannot open %s", filename);                              
        exit(1);                                                               
    }                                                                          

    word1Count = 0; word2Count = 0; lineCount = 1;                             
    while(fgets(line, sizeof(line), infile) != NULL) {                         
        char *p = line;                                                        
        lineCount++;                                                           
        while (*p != '\0' && *p != '\n') {                                     
            i = 0;                                                             
            while (*p != ' ' && *p != '\0' && *p != '\n') {                    
                wordInText[i++] = tolower(*p++);                               
            }                                                                  
            if (*p == ' ') {                                                   
                p++;                                                           
            }                                                                  
            wordInText[i] = '\0';                                              

            if(!strcmp(wordInText, inputWord1)) {                              
                word1Count++;                                                  
                if(word1Count == 1) {                                          
                    strncpy(firsAppear, line, sizeof(firsAppear));             

                }                                                              
            }                                                                  
            if(!strcmp(wordInText, inputWord2)) {                              
                word2Count++;                                                  
            }                                                                  
        }                                                                      
    }                                                                          
    printf("Word 1 appears %d times\n", word1Count);                           
    printf("Word 2 appears %d times\n", word2Count);                           
    printf("%s", firsAppear);                                                  
}