Menu
×
   ❮   
HTML CSS JAVASCRIPT SQL PYTHON JAVA PHP HOW TO W3.CSS C C++ C# BOOTSTRAP REACT MYSQL JQUERY EXCEL XML DJANGO NUMPY PANDAS NODEJS R TYPESCRIPT ANGULAR GIT POSTGRESQL MONGODB ASP AI GO KOTLIN SASS VUE DSA GEN AI SCIPY AWS CYBERSECURITY DATA SCIENCE
     ❯   

C stdio fwrite() Function

❮ C stdio Library


Example

Write content to a file:

FILE *fptr;
fptr = fopen("filename.txt", "a");

char content = "Hello World!";
fwrite(content, 1, 12, fptr);
printf("%d", position);

fclose(fptr);

Definition and Usage

The fwrite() function writes data from a block of memory into a file.

The fwrite() function is defined in the <stdio.h> header file.


Syntax

fwrite(const void * source, size_t size, size_t amount, FILE * fptr);

The size_t data type is a non-negative integer.

Parameter Values

Parameter Description
source Required. A pointer to a block of memory where the data is copied from.
size Required. The size of an element in the block of memory.
amount Required. The number of elements to read from the block of memory and write into the file.
fptr Required. A file pointer, usually created by the fopen() function.

Technical Details

Returns: A size_t value representing the number of elements that were written into the file.

❮ C stdio Library

×

Contact Sales

If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail:
sales@w3schools.com

Report Error

If you want to report an error, or if you want to make a suggestion, send us an e-mail:
help@w3schools.com

W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. While using W3Schools, you agree to have read and accepted our terms of use, cookie and privacy policy.

Copyright 1999-2024 by Refsnes Data. All Rights Reserved. W3Schools is Powered by W3.CSS.