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Function Fopen ()() in C

Explore Function Fopen ()() in C with clear explanations, practical examples, and useful tips.

Table of Contents

This guide covers function fopen ()() in c with practical context and easy-to-follow details. Use it to understand the subject and apply the information confidently.

Declare Function Fopen ()() in C

Below is the declaration for the function fopen () in C:

 FILE * fopen ( const char * filename , const char * mode ) 

Parameters

Filename - This is the string containing the file name to be opened.

Mode - This is the string containing a file access mode. It includes:

Mode Description "r" Open a file to read. File must exist "w" Create an empty file to write. If a file with the same name already exists, its content is removed and the file is treated as a new blank file "a" Append to a file. With write operations, append data at the end of the file. The file is created if it does not already exist "r +" Open a file to write and read. File must exist "w +" Create an empty file to write and read "a +" Open a file to read and append

Returns the value

This function returns a FILE pointer. Otherwise, NULL is returned and the errno global variable is set to indicate an error.

For example

The following C program illustrates the usage of the function fopen () in C:

 #include #include int main () { FILE * fp ; fp = fopen ( "baitapc.txt" , "w+" ); fprintf ( fp , "%s %s %s %s" , "Chung" , "toi" , "la" , "QTMTeam" ); fclose ( fp ); return ( 0 ); } 

Compiling and running the above program will create a baitap. T. Txt

Now follow the contents of the above file by using the following C program:

Compile and run the above C program to see the results:

According to Tutorialspoint

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FAQ

What should I check before following these steps?

Confirm device and software compatibility, save important data, and make sure you have the required permissions, files, and account access.

Why might the process not work?

Common causes include outdated software, missing permissions, incompatible hardware, an unstable connection, or completing a step in the wrong order.

Can I undo the changes if necessary?

That depends on the tool or setting. Use built-in restore options when available, keep a backup, and record the original configuration first.

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