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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

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