比较C，DevC ++中的字符串 [英] Compare Strings in C, DevC++

问题描述

我想建立一个文件管理系统，但我需要一些帮助。我似乎无法弄清楚如何实际比较C中的字符串。这是我目前的代码：

I wanted to make a file management system but I need some help with it. I can't seem to figure out how to actually compare strings in C. Here is my current code:

# include <stdlib.h>   // for exit()
# include <stdio.h>    // defines FILE


//project task
//ask for username and password of user.
//make 2 array (1 for username, 1 for password)
int pp;
//global list
  FILE *fptr;    // ptr to file for username
  char ch;
  FILE *x;

  FILE *fptr2;    // ptr to file for password
  char ch2;
  FILE *z;
  char theString[] = "First Mid Last";
  char theString1[100];
  char theString2[100];
  char zzzz[100];
  char storeuser[100];
//global list     
int main()
{
   
     
         
     if ((fptr = fopen("username.txt","r"))== NULL )  // open file in writing mode
      {
        printf("Can't open file username.txt\n");
        getch();
        exit(1);  // error return value
        }       
        
        
        
     if ((fptr2 = fopen("password.txt","r"))== NULL )  // open file in writing mode
      {
        printf("Can't open file password.txt\n");
        getch();
        exit(1);  // error return value
        }       
     printf("Enter your userame\n");
     
   scanf("%s", &theString1);
//   printf("%s", theString1);
     
     printf("Enter your password\n");
     
   scanf("%s", &theString2);
//   printf("%s", theString2);
     
     
     printf("%s", fptr);
     while ((ch = getc(fptr)) != EOF)
     
     
 
     printf("%c",ch);
     
     

     
     fclose(fptr);
     
     getch();
     
     return 0;
        
}

我想将theString1与username.txt中的文本进行比较，该文本正在使用fptr变量。

任何有关此问题的帮助都会被批评:)

谢谢。

I want to compare theString1 with the text in username.txt which is being accessed using the fptr variable.
Any help regarding this would be appricated :)
Thanks.

推荐答案

您的输入文件可能由多行组成，每行包含用户名和密码（可能用哈希函数编码）。因此，在username.txt文件中的行上执行循环。在每个循环迭代中：



a）从该行中提取用户名和密码

b）将用户名与theString1中的控制台输入进行比较。



你可以使用cmpstr或cmpistr（用于不区分大小写的比较）来比较theString1中的字符串和用户名。

Your input file does probably consist of multiple line, each containing a username and password (probably encoded with a hash function). So perform a loop over the lines in your username.txt file. In each loop iteration:

a) extract the username and password out of that line
b) compare the username with the console input in theString1.

You may use the cmpstr or cmpistr (for case-insensitive comparison) to compare the string in theString1 with the username.

这篇关于比较C，DevC ++中的字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！