rewind

From cppreference.com

< c‎ | io

Defined in header `<stdio.h>`
void rewind( FILE *stream );

Moves the file position indicator to the beginning of the given file stream.

The function is equivalent to fseek(stream, 0, SEEK_SET);, except that end-of-file and error indicators are cleared.

The function drops any effects from previous calls to ungetc.

Parameters

stream

file stream to modify

Return value

(none)

Example

This example shows how to read a file twice

Run this code

#include <stdio.h>
 
char str[20];
 
int main(void)
{
    FILE *f;
    char ch;
 
    f = fopen("file.txt", "w");
    for (ch = '0'; ch <= '9'; ch++) {
        fputc(ch, f);
    }
    fclose(f);
 
    f = fopen("file.txt", "r");
    fread(str, 1, 10, f);
    puts(str);
 
    rewind(f);
    fread(str, 1, 10, f);
    puts(str);
    fclose(f);
 
    return 0;
}

Output:

0123456789
0123456789

References

C11 standard (ISO/IEC 9899:2011):

7.21.9.5 The rewind function (p: 338)

C99 standard (ISO/IEC 9899:1999):

7.19.9.5 The rewind function (p: 304)

C89/C90 standard (ISO/IEC 9899:1990):

4.9.9.5 The rewind function

Language
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Type support
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