How to both read and write a file in C

Question

I want to both read from and write to a file  This doesn t work    static void Main string   args        StreamReader sr   new StreamReader   C  words txt        StreamWriter sw   new StreamWriter   C  words txt        How can I both read from and write to a file in C

User · Answer

You need a single stream  opened for both reading and writing   FileStream fileStream   new FileStream          c  words txt   FileMode OpenOrCreate         FileAccess ReadWrite  FileShare None

User · Answer

Don t forget the easy route       static void Main string   args                var text   File ReadAllText   C  words txt            File WriteAllText   C  words txt   text    DERP

User · Answer

Made an improvement code by  Ipsita - for use asynchronous read write file I O  readonly string logPath     FilePath       public async Task WriteToLogAsync string dataToWrite        TextReader tr   new StreamReader logPath       string data   await tr ReadLineAsync        tr Close         TextWriter tw   new StreamWriter logPath       await tw WriteLineAsync data   dataToWrite       tw Close          await WriteToLogAsync  Write this to file

User · Answer

you can try this  Filename txt  file will be created automatically in the bin- debug folder everytime you run this code or you can specify path of the file like    C        you can check   xistance of  Hello  by going to the bin -- debug folder  P S dont forget to add Console Readline   after this code snippet else console will not appear   TextWriter tw   new StreamWriter  filename txt            String text    Hello           tw WriteLine text           tw Close             TextReader tr   new StreamReader  filename txt            Console WriteLine tr ReadLine             tr Close

User · Answer

This thread seems to answer your question   simultaneous-read-write-a-file  Basically  what you need is to declare two FileStream  one for read operations  the other for write operations  Writer Filestream needs to open your file in  Append  mode

User · Answer

var fs   File Open  file name   FileMode OpenOrCreate  FileAccess ReadWrite   var sw   new StreamWriter fs   var sr   new StreamReader fs         fs Close      or sw Close      The key thing is to open the file with the FileAccess ReadWrite flag   You can then create whatever Stream String Binary Reader Writers you need using the initial FileStream

[c#] How to both read and write a file in C#

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