blocks|key|1417370|text|要从文件中单独读取每一行，请在while循环中使用fgets，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1417371|while(fgets(string,+sizeof(string),+file1)+!=+NULL)
{
...
}
fclose(file1);+|code-block|syntax|javascript|1417372|在循环内部，对每一行进行操作以反转它。|1417373|entityMap^0|F|5|P|5|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

To read each line separately from file use <code>fgets</code> in <code>while</code> loop as below,

<pre><code>while(fgets(string, sizeof(string), file1) != NULL)
{
...
}
fclose(file1); 
</code></pre>

Inside the loop operate on each line to reverse it.

blocks|key|1417401|text|您的代码中有相当多的逻辑错误。我建议使用其他的f*方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1417402|如果你想要一个简单的解决方案，打开文件，确定它的长度，创建两个文件大小的缓冲区，用文件的内容填充第一个缓冲区，然后执行一个循环，将相反的内容复制到另一个缓冲区，然后写回那个缓冲区。粗略地看起来像这样：|1417403|#include+<stdio.h>
#include+<string.h>

int+main()
{
++++FILE+*file;

++++file+=+fopen("StartingFile.txt",+"rt");
++++if+(file+==+NULL)
++++{
++++++++printf+("Error+-+Couldn't+open+file\n");
++++++++return+(-1);
++++}

++++fseek(file,+0,+SEEK_END);+//+move+file+pointer+to+end+of+file
++++long+size+=+ftell(file);+//+file+pointer+position+==+character+count+in+file
++++fseek(file,+0,+SEEK_SET);++//+move+back+to+beginning+of+file

++++char*+buffer+=+malloc(size+*+sizeof(char));

++++fread(buffer,+sizeof(char),+size,+file)+//+read+file+contents+to+buffer

++++for(long+i+=+0;+i+<+size/2;+%2B%2Bi)
++++{
++++++++buffer[i]+=+buffer[size-i-1];
++++}

++++fseek(file,+0,+SEEK_SET);+//+The+fread+set+the+file+pointer+to+the+end+so+we+need+to+put+it+to+the+front+again.

++++fwrite(buffer,+sizeof(char),+size,+file);+//+Write+reverted+content

++++delete+buffer;


++++fclose+(file);
}|code-block|syntax|javascript|1417404|我还没有测试它，它可能包含一些错误，因为我已经有一段时间没有用C语言编程了。无论如何，仍然使用C语言编程的唯一原因是效率，如果你想让你的程序高效，两个缓冲区的解决方案也不是最好的。至少在内存使用方面不是这样。|1417405|我强烈建议熟悉C中所有可用的函数(stdio等等)，cplusplus.com是一个很好的参考资料。|1417406|向您致敬，Xaser|1417407|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Your code has quite a few logical errors in it. I would recommend using other f* methods instead.

If you want an easy solution, open the file, determine its length, create two buffers of the size of the file, fill the first buffer with the file's contents and then do a loop to copy the reverse to the other buffer, then write that buffer back. Roughly that would look like this:

<pre><code>#include &lt;stdio.h&gt;
#include &lt;string.h&gt;

int main()
{
 FILE *file;

 file = fopen("StartingFile.txt", "rt");
 if (file == NULL)
 {
 printf ("Error - Couldn't open file\n");
 return (-1);
 }

 fseek(file, 0, SEEK_END); // move file pointer to end of file
 long size = ftell(file); // file pointer position == character count in file
 fseek(file, 0, SEEK_SET); // move back to beginning of file

 char* buffer = malloc(size * sizeof(char));

 fread(buffer, sizeof(char), size, file) // read file contents to buffer

 for(long i = 0; i &lt; size/2; ++i)
 {
 buffer[i] = buffer[size-i-1];
 }

 fseek(file, 0, SEEK_SET); // The fread set the file pointer to the end so we need to put it to the front again.

 fwrite(buffer, sizeof(char), size, file); // Write reverted content

 delete buffer;


 fclose (file);
}
</code></pre>

I haven't tested it and it may contain a few errors since I haven't programmed in C for some time. The only reason to still be programming in C anyways is efficiency and if you want your program to be efficient, the two buffer solution isn't the best either. At least not in terms of memory usage.

I highly recommend getting familiar with all the functions available in C (stdio and so on) cplusplus.com is a great reference for that.

Regards, Xaser

I'm trying to make a program that uses fgets to take the text from a preexisting file, invert it and then write it to another file. This is the code I've written so far:

<pre><code>#include &lt;stdio.h&gt;
#include &lt;string.h&gt;

int main()
{
 int c, d;
 FILE *file1, *file2;
 char string [100], *begin, *end, temp;

 file1 = fopen("StartingFile.txt", "rt");
 if (file1 == NULL)
 {
 printf ("Error - Couldn't open file\n");
 return (-1);
 }

 fgets(string, 100, file1);

 fclose (file1);
 begin = string;
 end = begin + strlen(string) - 1;

 while (end &gt; begin)
 {
 temp = *begin;
 *begin = *end;
 *end = temp;

 ++begin;
 --end;
 } 

 file2 = fopen("FinalFile.txt", "wt");
 fprintf (file2, "%s", string);
 fclose (file2);
 printf ("%s\n", string);

 return 0;
}
</code></pre>

It works fine if the text in the preexisting file is all in one line, but if it has more than one line, only the first one is inverted and written to the new file. I think that fgets can only read one line, so I think I'll have to use a loop, but I'm having trouble implementing it. Can someone give me a hand? Thanks in advance!

Reverse file text

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

我正在尝试编写一个程序，它使用fgets从预先存在的文件中获取文本，将其颠倒，然后将其写入另一个文件。这是我到目前为止写的代码：#include <stdio.h>#include <string.h>int main(){ int c, d; FILE *file1, *file2; char string [...

问反转文件文本
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问反转文件文本EN