fread

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Header File

stdio.h

Category

Input/output Routines

Prototype

size_t fread(void *ptr, size_t size, size_t n, FILE *stream);

Description

Reads data from a stream.

fread reads n items of data each of length size bytes from the given input stream into a block pointed to by ptr.

The total number of bytes read is (n * size).

Return Value

On success fread returns the number of items (not bytes) actually read.

On end-of-file or error it returns a short count (possibly 0).

Example



 #include <string.h>
 #include <stdio.h>
 int main(void)
 {
    FILE *stream;
    char msg[] = "this is a test";
    char buf[20];
    if ((stream = fopen("DUMMY.FIL", "w+"))
        == NULL)
    {
       fprintf(stderr, "Cannot open output file.\n");
       return 1;
    }
    /* write some data to the file */
    fwrite(msg, strlen(msg)+1, 1, stream);
    /* seek to the beginning of the file */
    fseek(stream, SEEK_SET, 0);
    /* read the data and display it */
    fread(buf, strlen(msg)+1, 1, stream);
    printf("%s\n", buf);
    fclose(stream);
    return 0;
 }



Portability



POSIX Win32 ANSI C ANSI C++

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