如何从文本文件中删除? [英] How can I delete from a text file?

问题描述

大家好，我有一个文本文件，称为dictionary.txt.基本上，我正在做两个选择的菜单，1.在字典中添加新单词，以及2.从字典中删除单词.现在我设法做菜单并添加新单词.但是，我一直坚持从文件中删除.我希望当用户输入"runners"时，在dictionary.txt中搜索该单词并将其删除.告诉您我在学校还没有涉及到的所有内容，但是我在这里正在寻找一些想法，以便我可以继续完成任务.我已经尝试了一些方法，但是正如我已经告诉您的那样，我还没有介绍它，所以我不知道该怎么做.我感谢所有的帮助.下面是我的程序.

Hi guys I have a text file which is known as dictionary.txt. Basically i am doing a menu of two choices, 1. add new words to dictionary and 2. delete words from dictionary. right now i managed to do the menu and add new words. However, I am stuck at deleting from a file. I want that when the user enters for example "runners" the word is searched in the dictionary.txt and it is deleted. To tell you everything I haven't covered it yet at school but I am looking for some ideas here so that I can move on with the task. I have tried some things but as I already told you, I haven't covered it yet so I don't know how to actually do it. I appreciate all the help. below is my program.

推荐答案

• 您打开两个文件:一个文件(用于读取)和一个新文件(用于写入).
• 您循环浏览第一个文件，依次读取每一行.
• 您将每行的内容与需要删除的单词进行比较.
• 如果该行与任何删除词都不匹配，则将其写入新文件.

约瑟夫，摘自我先前由理查德·乌尔文(Richard Urwin)回答的问题

Josuel, as taken from my previously answered question by Richard Urwin

您可以使用以下代码:

#include <stdio.h>

    int main()
    {
        FILE *fileptr1, *fileptr2;
        char filename[40];
        char ch;
        int delete_line, temp = 1;

        printf("Enter file name: ");
        scanf("%s", filename);
        //open file in read mode
        fileptr1 = fopen("c:\\CTEMP\\Dictionary.txt", "r");
        ch = getc(fileptr1);
        while (ch != EOF)
        {
            printf("%c", ch);
            ch = getc(fileptr1);
        }
        //rewind
        rewind(fileptr1);
        printf(" \n Enter line number of the line to be deleted:");
        scanf("%d", &delete_line);
        //open new file in write mode
        fileptr2 = fopen("replica.c", "w");
        ch = getc(fileptr1);
        while (ch != EOF)
        {
            ch = getc(fileptr1);
            if (ch == '\n')
            {
                temp++;
            }
            //except the line to be deleted
            if (temp != delete_line)
            {
                //copy all lines in file replica.c
                putc(ch, fileptr2);
            }
        }
        fclose(fileptr1);
        fclose(fileptr2);
        remove("c:\\CTEMP\\Dictionary.txt");
        //rename the file replica.c to original name
        rename("replica.c", "c:\\CTEMP\\Dictionary.txt");
        printf("\n The contents of file after being modified are as follows:\n");
        fileptr1 = fopen("c:\\CTEMP\\Dictionary.txt", "r");
        ch = getc(fileptr1);
        while (ch != EOF)
        {
            printf("%c", ch);
            ch = getc(fileptr1);
        }
        fclose(fileptr1);
        scanf_s("%d");
        return 0;

    }

这篇关于如何从文本文件中删除?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！