rewind

< c‎ | io
 
C
 
File input/output
Functions
File access
Direct input/output
Unformatted input/output
(C95)(C95)
(C95)
(C95)(C95)
(C95)
(C95)
(C95)
(C95)
Formatted input
Formatted output
File positioning
rewind
Error handling
Operations on files
(C11)
(C11)
 
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

See also

 moves the file position indicator to a specific location in a file
(function)