Question

我在c工作。我有两个文件。我想问一下，如果存在于第二个文件中，从第一个文件中测试每一行的最佳方法是什么。

我还需要一些示例代码。

THX

Answer 1

尝试使用diffviewer而不是自己编码？

http://meldmerge.org/

否则，在C中，从头到尾比较字符，记住各个位置的差异并打印出来？

Answer 2

由于问题有点模糊，“哈希”可能是一个有点模糊的答案。

Answer 3

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

int compareFiles(const char * filename_compared, const char *filename_checked, int *matched)
{
    int matches = 0;
    int lines = 0;
    char compare_line[10000];
    char check_line[10000];

    char *compare;
    char *check;
    FILE *f_compare;
    FILE *f_check;

    f_compare = fopen(filename_compared,"r");
    if ( f_compare == NULL ) 
    {  
        printf("ERROR %d opening %s\n",errno,filename_compared); 
        return EXIT_FAILURE; 
    } else { printf("opened %s\n",filename_compared); }

    f_check = fopen(filename_checked,"r");
    if ( f_check == NULL )  
    {  
        printf("ERROR %d opening %s\n",errno,filename_checked); 
        return EXIT_FAILURE; 
    } else { printf("opened %s\n",filename_checked); }
    compare = fgets(compare_line,sizeof(compare_line),f_compare);
    while (  ! feof(f_compare)  )
    {
       lines++;
       fseek(f_check,0,0);
       check = fgets(check_line,sizeof(check_line),f_check);
       while (  ! feof(f_check) )
       {
          if ( strcmp(compare_line,check_line) == 0 )
          {
             matches++;
             break;
          }
          check = fgets(check_line,sizeof(check_line),f_check);
       }
       compare = fgets(compare_line,sizeof(compare_line),f_compare);  
    } 
    *matched = matches;
    printf("%d lines read in first file and %d lines matched a line in the 2nd file\n",lines,matches);
    fclose(f_check);
    fclose(f_compare);
    return EXIT_SUCCESS;
}

int main(int argc, char *argv[])
{
    int matches;
    if ( argc < 3 )
    {
       printf("ERROR: You must enter the two input filenames\n");
       return EXIT_FAILURE;
    }
    int return_code = compareFiles(argv[1],argv[2],&matches);
    if ( return_code == EXIT_SUCCESS )
        printf("%d lines in %s matched a line in %s\n",matches, argv[1],argv[2]);
    else
       printf("there was an error in processing the files\n");
}

Answer 4

Just Angela，只是研究你所指的C书，只做家庭作业。它可能只有一整章文件处理。

对于初学者，你需要熟悉fopen（和fclose），fscanf，fseek和memcmp。

检查2个文件的c代码

4 个答案: