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# fwrite

Input-Output Functions

Write unformatted data from a buffer to a stream.

    size_t fwrite( const void *buffer, size_t size, size_t count, FILE *file_pointer);

buffer | The buffer containing the data.
size | The size of the buffer.
count | The number of bytes to store in the buffer.
file_pointer | A pointer to a file that will store the data.

## Return Values

If successful, the function returns the number of full items (not bytes) successfully written.

## Example

The following example gives values to a student record, sd, and then writes it to a file using fwrite.

Copy code

        #include <stdio.h>
        #ifdef unix
            char * filename = "/tmp/marks.txt";
        #else
            char * filename = "c:\\marks.txt";
        #endif
        struct student_data {
            int student_id;
            unsigned char marks[10];
        };
        FILE* file;
        struct student_data sd;
        int i;
        if ((file = fopen(filename, "w+")) == NULL) {
            lr_output_message ("Unable to create %s", filename);
            return -1;
        }
        sd.student_id = 1001;
    // Set the marks of student 1001
        for (i = 0; i < 10; i++)
             sd.marks[i] = (unsigned char)(85 + i);
    // Write student record to the file
            i = fwrite(&sd, sizeof(struct student_data), 1, file);
        if (i > 0)
            lr_output_message ("Successfully wrote %d record", i);
        fclose(file);

    Example: Output:
    Successfully wrote 1 record

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